diff --git a/changelog.d/sc-h4216-baseline.added.md b/changelog.d/sc-h4216-baseline.added.md
new file mode 100644
index 00000000000..420e050bcf4
--- /dev/null
+++ b/changelog.d/sc-h4216-baseline.added.md
@@ -0,0 +1 @@
+Move SC H4216 income tax reform from contributed reform to baseline, effective for tax years 2026 and later. This implements new tax rates (1.99%/5.21%), the SCIAD deduction with phaseout, and the 00 EITC cap.
diff --git a/policyengine_us/parameters/gov/contrib/states/sc/h4216/eitc/max.yaml b/policyengine_us/parameters/gov/contrib/states/sc/h4216/eitc/max.yaml
deleted file mode 100644
index 09cdbfde892..00000000000
--- a/policyengine_us/parameters/gov/contrib/states/sc/h4216/eitc/max.yaml
+++ /dev/null
@@ -1,12 +0,0 @@
-description: South Carolina H.4216 caps the state EITC at this amount.
-
-metadata:
-  unit: currency-USD
-  period: year
-  label: South Carolina H.4216 EITC maximum cap
-  reference:
-    - title: South Carolina H.4216 Section 7 - Section 12-6-3632
-      href: https://www.scstatehouse.gov/sess126_2025-2026/prever/4216_20260224.htm
-
-values:
-  2026-01-01: 200
diff --git a/policyengine_us/parameters/gov/contrib/states/sc/h4216/in_effect.yaml b/policyengine_us/parameters/gov/contrib/states/sc/h4216/in_effect.yaml
deleted file mode 100644
index e4965bb07e9..00000000000
--- a/policyengine_us/parameters/gov/contrib/states/sc/h4216/in_effect.yaml
+++ /dev/null
@@ -1,12 +0,0 @@
-description: The South Carolina H.4216 tax reform applies if this is true.
-
-metadata:
-  unit: bool
-  period: year
-  label: South Carolina H.4216 tax reform in effect
-  reference:
-    - title: South Carolina H.4216 (126th Session, 2025-2026)
-      href: https://www.scstatehouse.gov/sess126_2025-2026/prever/4216_20260224.htm
-
-values:
-  0000-01-01: false
diff --git a/policyengine_us/parameters/gov/contrib/states/sc/h4216/rates.yaml b/policyengine_us/parameters/gov/contrib/states/sc/h4216/rates.yaml
deleted file mode 100644
index 31fbf8e8c8f..00000000000
--- a/policyengine_us/parameters/gov/contrib/states/sc/h4216/rates.yaml
+++ /dev/null
@@ -1,24 +0,0 @@
-# Note: H.4216 Items 2-3 also include automatic rate reductions beginning
-# in 2027 if individual income tax revenues project to grow at least 5%
-# year-over-year. These future rate reductions are not modeled.
-description: South Carolina H.4216 establishes new income tax rates.
-
-metadata:
-  reference:
-    - title: South Carolina H.4216 Section 1 - Section 12-6-510(C)
-      href: https://www.scstatehouse.gov/sess126_2025-2026/prever/4216_20260224.htm
-  label: South Carolina H.4216 income tax rates
-  type: marginal_rate
-  threshold_unit: currency-USD
-  rate_unit: /1
-  period: year
-
-brackets:
-  - threshold:
-      2026-01-01: 0
-    rate:
-      2026-01-01: 0.0199
-  - threshold:
-      2026-01-01: 30_000
-    rate:
-      2026-01-01: 0.0521
diff --git a/policyengine_us/parameters/gov/contrib/states/sc/h4216/sciad/amount.yaml b/policyengine_us/parameters/gov/contrib/states/sc/h4216/sciad/amount.yaml
deleted file mode 100644
index a24c8cc57df..00000000000
--- a/policyengine_us/parameters/gov/contrib/states/sc/h4216/sciad/amount.yaml
+++ /dev/null
@@ -1,26 +0,0 @@
-description: South Carolina H.4216 provides the SC Income Adjusted Deduction (SCIAD) at these base amounts by filing status.
-
-metadata:
-  label: South Carolina H.4216 SCIAD base amount
-  period: year
-  unit: currency-USD
-  breakdown:
-    - filing_status
-  reference:
-    - title: South Carolina H.4216 Section 3 - Section 12-6-1140(15)(a)
-      href: https://www.scstatehouse.gov/sess126_2025-2026/prever/4216_20260224.htm
-
-SINGLE:
-  2026-01-01: 15_000
-
-SEPARATE:
-  2026-01-01: 15_000
-
-HEAD_OF_HOUSEHOLD:
-  2026-01-01: 22_500
-
-JOINT:
-  2026-01-01: 30_000
-
-SURVIVING_SPOUSE:
-  2026-01-01: 30_000
diff --git a/policyengine_us/parameters/gov/contrib/states/sc/h4216/sciad/phase_out/start.yaml b/policyengine_us/parameters/gov/contrib/states/sc/h4216/sciad/phase_out/start.yaml
deleted file mode 100644
index ceaa430ce56..00000000000
--- a/policyengine_us/parameters/gov/contrib/states/sc/h4216/sciad/phase_out/start.yaml
+++ /dev/null
@@ -1,26 +0,0 @@
-description: South Carolina H.4216 begins phasing out the SCIAD when AGI exceeds this threshold.
-
-metadata:
-  label: South Carolina H.4216 SCIAD phase-out start
-  period: year
-  unit: currency-USD
-  breakdown:
-    - filing_status
-  reference:
-    - title: South Carolina H.4216 Section 3 - Section 12-6-1140(15)(b)
-      href: https://www.scstatehouse.gov/sess126_2025-2026/prever/4216_20260224.htm
-
-SINGLE:
-  2026-01-01: 40_000
-
-SEPARATE:
-  2026-01-01: 40_000
-
-HEAD_OF_HOUSEHOLD:
-  2026-01-01: 60_000
-
-JOINT:
-  2026-01-01: 80_000
-
-SURVIVING_SPOUSE:
-  2026-01-01: 80_000
diff --git a/policyengine_us/parameters/gov/contrib/states/sc/h4216/sciad/phase_out/width.yaml b/policyengine_us/parameters/gov/contrib/states/sc/h4216/sciad/phase_out/width.yaml
deleted file mode 100644
index deae09c68c0..00000000000
--- a/policyengine_us/parameters/gov/contrib/states/sc/h4216/sciad/phase_out/width.yaml
+++ /dev/null
@@ -1,26 +0,0 @@
-description: South Carolina H.4216 fully phases out the SCIAD over this income range (the denominator in the phase-out formula).
-
-metadata:
-  label: South Carolina H.4216 SCIAD phase-out width
-  period: year
-  unit: currency-USD
-  breakdown:
-    - filing_status
-  reference:
-    - title: South Carolina H.4216 Section 3 - Section 12-6-1140(15)(b)
-      href: https://www.scstatehouse.gov/sess126_2025-2026/prever/4216_20260224.htm
-
-SINGLE:
-  2026-01-01: 55_000
-
-SEPARATE:
-  2026-01-01: 55_000
-
-HEAD_OF_HOUSEHOLD:
-  2026-01-01: 82_500
-
-JOINT:
-  2026-01-01: 110_000
-
-SURVIVING_SPOUSE:
-  2026-01-01: 110_000
diff --git a/policyengine_us/parameters/gov/states/sc/tax/income/credits/eitc/max.yaml b/policyengine_us/parameters/gov/states/sc/tax/income/credits/eitc/max.yaml
new file mode 100644
index 00000000000..7e10dc655b3
--- /dev/null
+++ b/policyengine_us/parameters/gov/states/sc/tax/income/credits/eitc/max.yaml
@@ -0,0 +1,13 @@
+description: South Carolina caps the state EITC at this amount.
+
+metadata:
+  unit: currency-USD
+  period: year
+  label: South Carolina EITC maximum cap
+  reference:
+    - title: SC H.4216 Section 7 - Section 12-6-3632
+      href: https://www.scstatehouse.gov/sess126_2025-2026/bills/4216.htm
+
+values:
+  0001-01-01: .inf
+  2026-01-01: 200
diff --git a/policyengine_us/parameters/gov/states/sc/tax/income/deductions/sciad/amount.yaml b/policyengine_us/parameters/gov/states/sc/tax/income/deductions/sciad/amount.yaml
new file mode 100644
index 00000000000..d0aa6750f1e
--- /dev/null
+++ b/policyengine_us/parameters/gov/states/sc/tax/income/deductions/sciad/amount.yaml
@@ -0,0 +1,26 @@
+description: South Carolina provides the SC Income Adjusted Deduction (SCIAD) at these base amounts by filing status.
+
+metadata:
+  label: South Carolina SCIAD base amount
+  period: year
+  unit: currency-USD
+  breakdown:
+    - filing_status
+  reference:
+    - title: SC H.4216 Section 3 - Section 12-6-1140(15)(a)
+      href: https://www.scstatehouse.gov/sess126_2025-2026/bills/4216.htm
+
+SINGLE:
+  2026-01-01: 15_000
+
+SEPARATE:
+  2026-01-01: 15_000
+
+HEAD_OF_HOUSEHOLD:
+  2026-01-01: 22_500
+
+JOINT:
+  2026-01-01: 30_000
+
+SURVIVING_SPOUSE:
+  2026-01-01: 30_000
diff --git a/policyengine_us/parameters/gov/states/sc/tax/income/deductions/sciad/in_effect.yaml b/policyengine_us/parameters/gov/states/sc/tax/income/deductions/sciad/in_effect.yaml
new file mode 100644
index 00000000000..57ddf1c5d92
--- /dev/null
+++ b/policyengine_us/parameters/gov/states/sc/tax/income/deductions/sciad/in_effect.yaml
@@ -0,0 +1,13 @@
+description: Whether the SC Income Adjusted Deduction (SCIAD) is in effect.
+
+metadata:
+  unit: bool
+  period: year
+  label: SC SCIAD in effect
+  reference:
+    - title: SC H.4216 Section 3 - Section 12-6-1140(15)
+      href: https://www.scstatehouse.gov/sess126_2025-2026/bills/4216.htm
+
+values:
+  0000-01-01: false
+  2026-01-01: true
diff --git a/policyengine_us/parameters/gov/states/sc/tax/income/deductions/sciad/phase_out/start.yaml b/policyengine_us/parameters/gov/states/sc/tax/income/deductions/sciad/phase_out/start.yaml
new file mode 100644
index 00000000000..662f2f1bbd8
--- /dev/null
+++ b/policyengine_us/parameters/gov/states/sc/tax/income/deductions/sciad/phase_out/start.yaml
@@ -0,0 +1,26 @@
+description: South Carolina begins phasing out the SCIAD when federal AGI exceeds this threshold.
+
+metadata:
+  label: South Carolina SCIAD phase-out start
+  period: year
+  unit: currency-USD
+  breakdown:
+    - filing_status
+  reference:
+    - title: SC H.4216 Section 3 - Section 12-6-1140(15)(b)
+      href: https://www.scstatehouse.gov/sess126_2025-2026/bills/4216.htm
+
+SINGLE:
+  2026-01-01: 40_000
+
+SEPARATE:
+  2026-01-01: 40_000
+
+HEAD_OF_HOUSEHOLD:
+  2026-01-01: 60_000
+
+JOINT:
+  2026-01-01: 80_000
+
+SURVIVING_SPOUSE:
+  2026-01-01: 80_000
diff --git a/policyengine_us/parameters/gov/states/sc/tax/income/deductions/sciad/phase_out/width.yaml b/policyengine_us/parameters/gov/states/sc/tax/income/deductions/sciad/phase_out/width.yaml
new file mode 100644
index 00000000000..c5828c7373f
--- /dev/null
+++ b/policyengine_us/parameters/gov/states/sc/tax/income/deductions/sciad/phase_out/width.yaml
@@ -0,0 +1,26 @@
+description: South Carolina fully phases out the SCIAD over this income range (the denominator in the phase-out formula).
+
+metadata:
+  label: South Carolina SCIAD phase-out width
+  period: year
+  unit: currency-USD
+  breakdown:
+    - filing_status
+  reference:
+    - title: SC H.4216 Section 3 - Section 12-6-1140(15)(b)
+      href: https://www.scstatehouse.gov/sess126_2025-2026/bills/4216.htm
+
+SINGLE:
+  2026-01-01: 55_000
+
+SEPARATE:
+  2026-01-01: 55_000
+
+HEAD_OF_HOUSEHOLD:
+  2026-01-01: 82_500
+
+JOINT:
+  2026-01-01: 110_000
+
+SURVIVING_SPOUSE:
+  2026-01-01: 110_000
diff --git a/policyengine_us/parameters/gov/states/sc/tax/income/rates.yaml b/policyengine_us/parameters/gov/states/sc/tax/income/rates.yaml
index b96a0427263..916aee34dc3 100644
--- a/policyengine_us/parameters/gov/states/sc/tax/income/rates.yaml
+++ b/policyengine_us/parameters/gov/states/sc/tax/income/rates.yaml
@@ -1,10 +1,14 @@
 description: South Carolina taxes the income of individuals at this rate.
+# Note: H.4216 Items 2-3 also include automatic rate reductions beginning
+# in 2027 if individual income tax revenues project to grow at least 5%
+# year-over-year. These future rate reductions are not modeled.
 brackets:
  - threshold:
      1994-01-01: 0
    rate:
      1994-01-01: 0.025
      2021-01-01: 0
+     2026-01-01: 0.0199
  - threshold:
      1994-01-01: 2_220
      2021-01-01: 3_110
@@ -12,6 +16,7 @@ brackets:
      2023-01-01: 3_330
      2024-01-01: 3_460
      2025-01-01: 3_560
+     2026-01-01: 30_000
    metadata:
       uprating: gov.irs.uprating
       rounding:
@@ -19,6 +24,7 @@ brackets:
         interval: 10
    rate:
      1994-01-01: 0.03
+     2026-01-01: 0.0521
  - threshold:
      1994-01-01: 4_440
      2021-01-01: 6_220
@@ -26,6 +32,7 @@ brackets:
      2023-01-01: 16_680
      2024-01-01: 17_330
      2025-01-01: 17_830
+     2026-01-01: .inf
    metadata:
       uprating: gov.irs.uprating
       rounding:
@@ -63,6 +70,8 @@ brackets:
 
 metadata:
   reference:
+    - title: SC H.4216 Section 1 - Section 12-6-510(C) (2026+)
+      href: https://www.scstatehouse.gov/sess126_2025-2026/bills/4216.htm
     - title: SC 1040 Instructions 2025
       href: https://dor.sc.gov/sites/dor/files/forms/SC1040Instr_2025.pdf#page=1
     - title: SC 2024 Income Tax Chart
diff --git a/policyengine_us/parameters/gov/states/sc/tax/income/subtractions/subtractions.yaml b/policyengine_us/parameters/gov/states/sc/tax/income/subtractions/subtractions.yaml
index 45e7c22ec84..6cafb26addd 100644
--- a/policyengine_us/parameters/gov/states/sc/tax/income/subtractions/subtractions.yaml
+++ b/policyengine_us/parameters/gov/states/sc/tax/income/subtractions/subtractions.yaml
@@ -4,28 +4,44 @@ values:
     - salt_refund_income
     - disability_benefits #include tax disability benefits
     - sc_net_capital_gain_deduction
-    - investment_in_529_plan  
+    - investment_in_529_plan
     - us_govt_interest
     - taxable_social_security
     - sc_military_deduction
     - sc_retirement_deduction
     - sc_senior_exemption
     - sc_young_child_deduction
-    - sc_dependent_exemption 
+    - sc_dependent_exemption
     # - Out of state income/gain
-    # - Volunteer deductions 
+    # - Volunteer deductions
     # - Active Trade or Business Income deduction
     # - Certain nontaxable National Guard or Reserve pay
     # - Negative amount of federal taxable income
-    # - Subsistence allowance 
+    # - Subsistence allowance
     # - Consumer Protection Services
-    # - Other subtractions 
+    # - Other subtractions
+  # H.4216 adds the SCIAD starting 2026
+  2026-01-01:
+    - salt_refund_income
+    - disability_benefits
+    - sc_net_capital_gain_deduction
+    - investment_in_529_plan
+    - us_govt_interest
+    - taxable_social_security
+    - sc_military_deduction
+    - sc_retirement_deduction
+    - sc_senior_exemption
+    - sc_young_child_deduction
+    - sc_dependent_exemption
+    - sc_sciad 
 
 metadata:
   unit: list
   period: year
-  label: South Carolina federal taxable income subtractions 
+  label: South Carolina federal taxable income subtractions
   reference:
+    - title: SC H.4216 Section 3 - Section 12-6-1140(15) (2026+)
+      href: https://www.scstatehouse.gov/sess126_2025-2026/bills/4216.htm
     - title: SC 1040 tax form instructions (2025)
       href: https://dor.sc.gov/sites/dor/files/forms/SC1040Instr_2025.pdf#page=8
     - title: SC 1040 tax form (2021)
diff --git a/policyengine_us/reforms/reforms.py b/policyengine_us/reforms/reforms.py
index f774002d35c..2c2b6d2029a 100644
--- a/policyengine_us/reforms/reforms.py
+++ b/policyengine_us/reforms/reforms.py
@@ -25,7 +25,6 @@
 from .states.ny.a04038 import create_ny_a04038_enhanced_escc_infants_reform
 from .states.ny.s9110 import create_ny_s9110_reform
 from .states.sc.h3492 import create_sc_h3492_eitc_refundable_reform
-from .states.sc.h4216 import create_sc_h4216_reform
 from .states.ny.a06774 import create_ny_a06774_enhanced_cdcc_reform
 from .states.ny.s04487 import create_ny_s04487_newborn_credit_reform
 from .harris.lift.middle_class_tax_credit import (
@@ -280,7 +279,6 @@ def create_structural_reforms_from_parameters(parameters, period):
     sc_h3492_eitc_refundable = create_sc_h3492_eitc_refundable_reform(
         parameters, period
     )
-    sc_h4216 = create_sc_h4216_reform(parameters, period)
     ny_a06774_enhanced_cdcc = create_ny_a06774_enhanced_cdcc_reform(parameters, period)
     ny_s04487_newborn_credit = create_ny_s04487_newborn_credit_reform(
         parameters, period
@@ -445,7 +443,6 @@ def create_structural_reforms_from_parameters(parameters, period):
         ny_a04038_enhanced_escc_infants,
         ny_s9110,
         sc_h3492_eitc_refundable,
-        sc_h4216,
         ny_a06774_enhanced_cdcc,
         ny_s04487_newborn_credit,
         middle_class_tax_credit,
diff --git a/policyengine_us/reforms/states/sc/h4216/__init__.py b/policyengine_us/reforms/states/sc/h4216/__init__.py
deleted file mode 100644
index 3dba992e8d2..00000000000
--- a/policyengine_us/reforms/states/sc/h4216/__init__.py
+++ /dev/null
@@ -1 +0,0 @@
-from .sc_h4216 import create_sc_h4216_reform, sc_h4216
diff --git a/policyengine_us/reforms/states/sc/h4216/sc_h4216.py b/policyengine_us/reforms/states/sc/h4216/sc_h4216.py
deleted file mode 100644
index f65bfd1ebe3..00000000000
--- a/policyengine_us/reforms/states/sc/h4216/sc_h4216.py
+++ /dev/null
@@ -1,137 +0,0 @@
-from policyengine_us.model_api import *
-from policyengine_core.periods import period as period_
-
-
-def create_sc_h4216() -> Reform:
-    """
-    South Carolina H.4216 - Comprehensive Income Tax Reform
-
-    This bill makes several changes to SC income tax:
-    1. Caps the SC EITC at $200 (Section 7)
-    2. Creates the SC Income Adjusted Deduction (SCIAD) replacing federal
-       standard deduction (Section 3)
-    3. Establishes new tax rates: 1.99% up to $30k, 5.21% above (Section 1)
-
-    Reference: https://www.scstatehouse.gov/sess126_2025-2026/prever/4216_20260224.htm
-    """
-
-    class sc_eitc(Variable):
-        value_type = float
-        entity = TaxUnit
-        label = "South Carolina EITC under H.4216"
-        unit = USD
-        definition_period = YEAR
-        reference = (
-            "https://www.scstatehouse.gov/sess126_2025-2026/prever/4216_20260224.htm",
-            "https://dor.sc.gov/forms-site/Forms/TC60_2021.pdf",
-        )
-        defined_for = StateCode.SC
-
-        def formula(tax_unit, period, parameters):
-            federal_eitc = tax_unit("eitc", period)
-            p = parameters(period).gov.states.sc.tax.income.credits.eitc
-            p_h4216 = parameters(period).gov.contrib.states.sc.h4216.eitc
-            # Calculate 125% of federal EITC, then cap at $200
-            uncapped = np.round(federal_eitc * p.rate, 1)
-            return min_(uncapped, p_h4216.max)
-
-    class sc_sciad(Variable):
-        value_type = float
-        entity = TaxUnit
-        label = "South Carolina Income Adjusted Deduction (SCIAD)"
-        unit = USD
-        definition_period = YEAR
-        reference = (
-            "https://www.scstatehouse.gov/sess126_2025-2026/prever/4216_20260224.htm"
-        )
-        defined_for = StateCode.SC
-
-        def formula(tax_unit, period, parameters):
-            p = parameters(period).gov.contrib.states.sc.h4216.sciad
-            filing_status = tax_unit("filing_status", period)
-            agi = tax_unit("adjusted_gross_income", period)
-
-            # Get base amount and phase-out parameters by filing status
-            base_amount = p.amount[filing_status]
-            phase_out_start = p.phase_out.start[filing_status]
-            phase_out_width = p.phase_out.width[filing_status]
-
-            # Calculate phase-out reduction
-            # Formula: deduction * (1 - (AGI - phase_out_start) / width)
-            excess_agi = max_(agi - phase_out_start, 0)
-            phase_out_fraction = min_(excess_agi / phase_out_width, 1)
-            raw_sciad = max_(base_amount * (1 - phase_out_fraction), 0)
-            # Per H.4216 Section 3, round down to nearest $10
-            return np.floor(raw_sciad / 10) * 10
-
-    class sc_taxable_income(Variable):
-        value_type = float
-        entity = TaxUnit
-        label = "South Carolina taxable income under H.4216"
-        defined_for = StateCode.SC
-        unit = USD
-        definition_period = YEAR
-        reference = (
-            "https://www.scstatehouse.gov/sess126_2025-2026/prever/4216_20260224.htm"
-        )
-
-        def formula(tax_unit, period, parameters):
-            # Start with federal AGI (H.4216 replaces federal std/itemized
-            # with SCIAD). Baseline sc_additions (QBI addback, SALT addback)
-            # exist to undo federal deductions already embedded in federal
-            # taxable_income; since we start from AGI those deductions were
-            # never taken, so additions must be excluded.
-            agi = tax_unit("adjusted_gross_income", period)
-            subtractions = tax_unit("sc_subtractions", period)
-            sciad = tax_unit("sc_sciad", period)
-            return max_(0, agi - subtractions - sciad)
-
-    class sc_income_tax_before_non_refundable_credits(Variable):
-        value_type = float
-        entity = TaxUnit
-        label = "South Carolina income tax before non-refundable credits under H.4216"
-        defined_for = StateCode.SC
-        unit = USD
-        definition_period = YEAR
-        reference = (
-            "https://www.scstatehouse.gov/sess126_2025-2026/prever/4216_20260224.htm"
-        )
-
-        def formula(tax_unit, period, parameters):
-            taxable_income = tax_unit("sc_taxable_income", period)
-            # Use H.4216 rates instead of baseline rates
-            p = parameters(period).gov.contrib.states.sc.h4216.rates
-            return p.calc(taxable_income)
-
-    class reform(Reform):
-        def apply(self):
-            self.update_variable(sc_eitc)
-            self.update_variable(sc_sciad)
-            self.update_variable(sc_taxable_income)
-            self.update_variable(sc_income_tax_before_non_refundable_credits)
-
-    return reform
-
-
-def create_sc_h4216_reform(parameters, period, bypass: bool = False):
-    if bypass:
-        return create_sc_h4216()
-
-    p = parameters.gov.contrib.states.sc.h4216
-
-    reform_active = False
-    current_period = period_(period)
-
-    for _ in range(5):
-        if p(current_period).in_effect:
-            reform_active = True
-            break
-        current_period = current_period.offset(1, "year")
-
-    if reform_active:
-        return create_sc_h4216()
-    else:
-        return None
-
-
-sc_h4216 = create_sc_h4216_reform(None, None, bypass=True)
diff --git a/policyengine_us/tests/policy/baseline/gov/states/sc/tax/income/sc_h4216_baseline.yaml b/policyengine_us/tests/policy/baseline/gov/states/sc/tax/income/sc_h4216_baseline.yaml
new file mode 100644
index 00000000000..e8c839c01c0
--- /dev/null
+++ b/policyengine_us/tests/policy/baseline/gov/states/sc/tax/income/sc_h4216_baseline.yaml
@@ -0,0 +1,326 @@
+# SC H.4216 Baseline Tests (2026+)
+# Tests the comprehensive tax reform in baseline:
+# 1. EITC cap at $200
+# 2. SC Income Adjusted Deduction (SCIAD)
+# 3. New tax rates (1.99% / 5.21%)
+# Reference: https://www.scstatehouse.gov/sess126_2025-2026/bills/4216.htm
+
+# EITC Cap Tests
+
+- name: SC EITC capped at $200 for high federal EITC (2026)
+  period: 2026
+  absolute_error_margin: 0.1
+  input:
+    people:
+      person1:
+        age: 30
+        is_tax_unit_head: true
+    tax_units:
+      tax_unit:
+        members: [person1]
+        eitc: 500
+    households:
+      household:
+        members: [person1]
+        state_code: SC
+  output:
+    # Federal EITC = $500
+    # SC EITC = min($500 * 1.25, $200) = min($625, $200) = $200
+    sc_eitc: 200
+
+- name: SC EITC below cap (2026)
+  period: 2026
+  absolute_error_margin: 0.1
+  input:
+    people:
+      person1:
+        age: 30
+        is_tax_unit_head: true
+    tax_units:
+      tax_unit:
+        members: [person1]
+        eitc: 100
+    households:
+      household:
+        members: [person1]
+        state_code: SC
+  output:
+    # Federal EITC = $100
+    # SC EITC = min($100 * 1.25, $200) = min($125, $200) = $125
+    sc_eitc: 125
+
+- name: SC EITC has no cap before 2026
+  period: 2025
+  absolute_error_margin: 0.1
+  input:
+    people:
+      person1:
+        age: 30
+        is_tax_unit_head: true
+    tax_units:
+      tax_unit:
+        members: [person1]
+        eitc: 500
+    households:
+      household:
+        members: [person1]
+        state_code: SC
+  output:
+    # Federal EITC = $500
+    # SC EITC = $500 * 1.25 = $625 (no cap in 2025)
+    sc_eitc: 625
+
+# SCIAD Tests
+
+- name: SCIAD for single filer below phase-out (2026)
+  period: 2026
+  absolute_error_margin: 0.1
+  input:
+    people:
+      person1:
+        age: 30
+        is_tax_unit_head: true
+        employment_income: 35_000
+    tax_units:
+      tax_unit:
+        members: [person1]
+    households:
+      household:
+        members: [person1]
+        state_code: SC
+  output:
+    # AGI $35k < phase-out start $40k, full SCIAD
+    sc_sciad: 15_000
+
+- name: SCIAD for single filer in phase-out range (2026)
+  period: 2026
+  absolute_error_margin: 0.1
+  input:
+    people:
+      person1:
+        age: 30
+        is_tax_unit_head: true
+        employment_income: 67_500
+    tax_units:
+      tax_unit:
+        members: [person1]
+    households:
+      household:
+        members: [person1]
+        state_code: SC
+  output:
+    # AGI $67,500, phase-out start $40k, width $55k
+    # Excess = $67,500 - $40,000 = $27,500
+    # Phase-out fraction = $27,500 / $55,000 = 0.5
+    # Reduction = $15,000 * 0.5 = $7,500
+    # SCIAD = $15,000 - $7,500 = $7,500
+    sc_sciad: 7_500
+
+- name: SCIAD fully phased out for high income single (2026)
+  period: 2026
+  absolute_error_margin: 0.1
+  input:
+    people:
+      person1:
+        age: 30
+        is_tax_unit_head: true
+        employment_income: 100_000
+    tax_units:
+      tax_unit:
+        members: [person1]
+    households:
+      household:
+        members: [person1]
+        state_code: SC
+  output:
+    # AGI $100k > phase-out end $95k ($40k + $55k)
+    # SCIAD fully phased out
+    sc_sciad: 0
+
+- name: SCIAD for joint filer below phase-out (2026)
+  period: 2026
+  absolute_error_margin: 0.1
+  input:
+    people:
+      person1:
+        age: 35
+        is_tax_unit_head: true
+        employment_income: 40_000
+      person2:
+        age: 33
+        is_tax_unit_spouse: true
+        employment_income: 35_000
+    tax_units:
+      tax_unit:
+        members: [person1, person2]
+        filing_status: JOINT
+    households:
+      household:
+        members: [person1, person2]
+        state_code: SC
+  output:
+    # AGI $75k < phase-out start $80k, full SCIAD
+    sc_sciad: 30_000
+
+- name: SCIAD for head of household (2026)
+  period: 2026
+  absolute_error_margin: 0.1
+  input:
+    people:
+      person1:
+        age: 35
+        is_tax_unit_head: true
+        employment_income: 55_000
+      person2:
+        age: 10
+        is_tax_unit_dependent: true
+    tax_units:
+      tax_unit:
+        members: [person1, person2]
+        filing_status: HEAD_OF_HOUSEHOLD
+    households:
+      household:
+        members: [person1, person2]
+        state_code: SC
+  output:
+    # AGI $55k < phase-out start $60k, full SCIAD
+    sc_sciad: 22_500
+
+- name: SCIAD is zero before 2026
+  period: 2025
+  absolute_error_margin: 0.1
+  input:
+    people:
+      person1:
+        age: 30
+        is_tax_unit_head: true
+        employment_income: 35_000
+    tax_units:
+      tax_unit:
+        members: [person1]
+    households:
+      household:
+        members: [person1]
+        state_code: SC
+  output:
+    # SCIAD doesn't exist before 2026
+    sc_sciad: 0
+
+# Tax Rate Tests
+
+- name: Tax at 1.99% rate for income under $30k (2026)
+  period: 2026
+  absolute_error_margin: 0.1
+  input:
+    people:
+      person1:
+        age: 30
+        is_tax_unit_head: true
+    tax_units:
+      tax_unit:
+        members: [person1]
+        adjusted_gross_income: 20_000
+    households:
+      household:
+        members: [person1]
+        state_code: SC
+  output:
+    # AGI $20k < SCIAD $15k phase-out, so SCIAD = $15k (below $40k AGI)
+    # Actually AGI $20k means full SCIAD of $15k
+    # SC taxable income = $20k - $15k = $5k
+    # Tax = $5k * 1.99% = $99.50
+    sc_income_tax_before_non_refundable_credits: 99.5
+
+- name: Tax calculation with new rates above $30k threshold (2026)
+  period: 2026
+  absolute_error_margin: 1
+  input:
+    people:
+      person1:
+        age: 30
+        is_tax_unit_head: true
+        employment_income: 100_000
+    tax_units:
+      tax_unit:
+        members: [person1]
+    households:
+      household:
+        members: [person1]
+        state_code: SC
+  output:
+    # AGI $100k, SCIAD $0 (fully phased out)
+    # Taxable income = $100k
+    # Tax = $30k * 1.99% + $70k * 5.21% = $597 + $3,647 = $4,244
+    sc_income_tax_before_non_refundable_credits: 4_244
+
+# Taxable Income Tests
+
+- name: SC taxable income starts from AGI in 2026
+  period: 2026
+  absolute_error_margin: 0.1
+  input:
+    people:
+      person1:
+        age: 30
+        is_tax_unit_head: true
+        employment_income: 50_000
+    tax_units:
+      tax_unit:
+        members: [person1]
+    households:
+      household:
+        members: [person1]
+        state_code: SC
+  output:
+    # AGI $50k, SCIAD phased out partially
+    # Excess = $50k - $40k = $10k
+    # Phase-out fraction = $10k / $55k = 0.18182
+    # Reduction = $15,000 * 0.18182 = $2,727.27, rounded to $2,720
+    # SCIAD = $15,000 - $2,720 = $12,280
+    # But wait - formula is: reduction = base * fraction, then round DOWN to $10
+    # reduction = $15,000 * 0.18182 = $2,727.27 -> floor($2,727.27/10)*10 = $2,720
+    # SCIAD = max(0, $15,000 - $2,720) = $12,280
+    sc_sciad: 12_280
+
+- name: Zero income results in zero tax (2026)
+  period: 2026
+  absolute_error_margin: 0.1
+  input:
+    people:
+      person1:
+        age: 30
+        is_tax_unit_head: true
+        employment_income: 0
+    tax_units:
+      tax_unit:
+        members: [person1]
+    households:
+      household:
+        members: [person1]
+        state_code: SC
+  output:
+    sc_sciad: 15_000
+    sc_taxable_income: 0
+    sc_income_tax_before_non_refundable_credits: 0
+
+- name: Non-SC resident gets zero for SC variables
+  period: 2026
+  absolute_error_margin: 0.1
+  input:
+    people:
+      person1:
+        age: 30
+        is_tax_unit_head: true
+        employment_income: 50_000
+    tax_units:
+      tax_unit:
+        members: [person1]
+    households:
+      household:
+        members: [person1]
+        state_code: NY
+  output:
+    sc_sciad: 0
+    sc_eitc: 0
+    sc_taxable_income: 0
+    sc_income_tax_before_non_refundable_credits: 0
diff --git a/policyengine_us/tests/policy/contrib/states/sc/h4216/sc_h4216.yaml b/policyengine_us/tests/policy/contrib/states/sc/h4216/sc_h4216.yaml
deleted file mode 100644
index 46d544f0668..00000000000
--- a/policyengine_us/tests/policy/contrib/states/sc/h4216/sc_h4216.yaml
+++ /dev/null
@@ -1,1020 +0,0 @@
-# SC H.4216 Tax Reform Tests
-# Tests the comprehensive tax reform including:
-# 1. EITC cap at $200
-# 2. SC Income Adjusted Deduction (SCIAD)
-# 3. New tax rates (1.99% / 5.21%)
-
-# EITC Cap Tests
-
-- name: Case 1, EITC capped at $200 for high federal EITC.
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 30
-        is_tax_unit_head: true
-        employment_income: 20_000
-      person2:
-        age: 5
-        is_tax_unit_dependent: true
-    tax_units:
-      tax_unit:
-        members: [person1, person2]
-    households:
-      household:
-        members: [person1, person2]
-        state_code: SC
-  output:
-    # Federal EITC at $20k with 1 child is substantial (~$3,733)
-    # SC EITC = min($3,733 * 1.25, $200) = min($4,666, $200) = $200
-    sc_eitc: 200
-
-- name: Case 2, EITC genuinely below cap with direct eitc input.
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 30
-        is_tax_unit_head: true
-    tax_units:
-      tax_unit:
-        members: [person1]
-        eitc: 100
-    households:
-      household:
-        members: [person1]
-        state_code: SC
-  output:
-    # Federal EITC = $100 (set directly)
-    # SC EITC = min($100 * 1.25, $200) = min($125, $200) = $125
-    sc_eitc: 125
-
-- name: Case 3, zero federal EITC produces zero state EITC.
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 30
-        is_tax_unit_head: true
-    tax_units:
-      tax_unit:
-        members: [person1]
-        eitc: 0
-    households:
-      household:
-        members: [person1]
-        state_code: SC
-  output:
-    # Federal EITC = $0
-    # SC EITC = min($0 * 1.25, $200) = $0
-    sc_eitc: 0
-
-- name: Case 4, EITC exactly at cap boundary.
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 30
-        is_tax_unit_head: true
-    tax_units:
-      tax_unit:
-        members: [person1]
-        eitc: 160
-    households:
-      household:
-        members: [person1]
-        state_code: SC
-  output:
-    # Federal EITC = $160
-    # SC EITC = min($160 * 1.25, $200) = min($200, $200) = $200
-    # Exactly at cap
-    sc_eitc: 200
-
-# SCIAD Tests
-
-- name: Case 5, SCIAD for single filer below phase-out.
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 30
-        is_tax_unit_head: true
-        employment_income: 35_000
-    tax_units:
-      tax_unit:
-        members: [person1]
-    households:
-      household:
-        members: [person1]
-        state_code: SC
-  output:
-    # AGI $35k < phase-out start $40k, full SCIAD
-    sc_sciad: 15_000
-
-- name: Case 6, SCIAD for single filer in phase-out range.
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 30
-        is_tax_unit_head: true
-        employment_income: 67_500
-    tax_units:
-      tax_unit:
-        members: [person1]
-    households:
-      household:
-        members: [person1]
-        state_code: SC
-  output:
-    # AGI $67,500, phase-out start $40k, width $55k
-    # Excess = $67,500 - $40,000 = $27,500
-    # Phase-out fraction = $27,500 / $55,000 = 0.5
-    # SCIAD = $15,000 * (1 - 0.5) = $7,500
-    sc_sciad: 7_500
-
-- name: Case 7, SCIAD fully phased out for high income single.
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 30
-        is_tax_unit_head: true
-        employment_income: 100_000
-    tax_units:
-      tax_unit:
-        members: [person1]
-    households:
-      household:
-        members: [person1]
-        state_code: SC
-  output:
-    # AGI $100k > phase-out end $95k ($40k + $55k)
-    # SCIAD fully phased out
-    sc_sciad: 0
-
-- name: Case 8, SCIAD for joint filer below phase-out.
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 35
-        is_tax_unit_head: true
-        employment_income: 40_000
-      person2:
-        age: 33
-        is_tax_unit_spouse: true
-        employment_income: 35_000
-    tax_units:
-      tax_unit:
-        members: [person1, person2]
-        filing_status: JOINT
-    households:
-      household:
-        members: [person1, person2]
-        state_code: SC
-  output:
-    # AGI $75k < phase-out start $80k, full SCIAD
-    sc_sciad: 30_000
-
-- name: Case 9, SCIAD for joint filer in phase-out range.
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 35
-        is_tax_unit_head: true
-        employment_income: 75_000
-      person2:
-        age: 33
-        is_tax_unit_spouse: true
-        employment_income: 60_000
-    tax_units:
-      tax_unit:
-        members: [person1, person2]
-        filing_status: JOINT
-    households:
-      household:
-        members: [person1, person2]
-        state_code: SC
-  output:
-    # AGI $135k, phase-out start $80k, width $110k
-    # Excess = $135,000 - $80,000 = $55,000
-    # Phase-out fraction = $55,000 / $110,000 = 0.5
-    # SCIAD = $30,000 * (1 - 0.5) = $15,000
-    sc_sciad: 15_000
-
-- name: Case 10, SCIAD for head of household in phase-out range.
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 35
-        is_tax_unit_head: true
-        employment_income: 101_250
-      person2:
-        age: 10
-        is_tax_unit_dependent: true
-    tax_units:
-      tax_unit:
-        members: [person1, person2]
-        filing_status: HEAD_OF_HOUSEHOLD
-    households:
-      household:
-        members: [person1, person2]
-        state_code: SC
-  output:
-    # AGI $101,250, phase-out start $60k, width $82,500
-    # Excess = $101,250 - $60,000 = $41,250
-    # Phase-out fraction = $41,250 / $82,500 = 0.5
-    # SCIAD = $22,500 * (1 - 0.5) = $11,250
-    sc_sciad: 11_250
-
-# Tax Rate Tests
-
-- name: Case 11, tax calculation with new rates below $30k threshold.
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 30
-        is_tax_unit_head: true
-        employment_income: 35_000
-    tax_units:
-      tax_unit:
-        members: [person1]
-    households:
-      household:
-        members: [person1]
-        state_code: SC
-  output:
-    # AGI $35k, SCIAD $15k (below phase-out)
-    # Taxable income = $35k - $15k = $20k
-    # Tax = $20k * 1.99% = $398
-    sc_income_tax_before_non_refundable_credits: 398
-
-- name: Case 12, tax calculation with new rates above $30k threshold.
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 30
-        is_tax_unit_head: true
-        employment_income: 100_000
-    tax_units:
-      tax_unit:
-        members: [person1]
-    households:
-      household:
-        members: [person1]
-        state_code: SC
-  output:
-    # AGI $100k, SCIAD $0 (fully phased out)
-    # Taxable income = $100k
-    # Tax = $30k * 1.99% + $70k * 5.21% = $597 + $3,647 = $4,244
-    sc_income_tax_before_non_refundable_credits: 4_244
-
-- name: Case 13, non-SC resident gets zero for all reform variables.
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 30
-        is_tax_unit_head: true
-        employment_income: 50_000
-    tax_units:
-      tax_unit:
-        members: [person1]
-    households:
-      household:
-        members: [person1]
-        state_code: NY
-  output:
-    sc_sciad: 0
-    sc_eitc: 0
-    sc_taxable_income: 0
-    sc_income_tax_before_non_refundable_credits: 0
-
-# Boundary Tests - SCIAD Phase-out
-
-- name: Case 14, SCIAD at exactly phase-out start (single).
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 30
-        is_tax_unit_head: true
-        employment_income: 40_000
-    tax_units:
-      tax_unit:
-        members: [person1]
-    households:
-      household:
-        members: [person1]
-        state_code: SC
-  output:
-    # AGI $40k = phase-out start, full SCIAD
-    sc_sciad: 15_000
-
-- name: Case 15, SCIAD one dollar above phase-out start (single).
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 30
-        is_tax_unit_head: true
-        employment_income: 40_001
-    tax_units:
-      tax_unit:
-        members: [person1]
-    households:
-      household:
-        members: [person1]
-        state_code: SC
-  output:
-    # AGI $40,001, excess = $1
-    # Phase-out fraction = $1 / $55,000 = 0.0000182
-    # Raw SCIAD = $15,000 * (1 - 0.0000182) = $14,999.73
-    # Rounded down to nearest $10: $14,990
-    sc_sciad: 14_990
-
-- name: Case 16, SCIAD at exactly phase-out end (single).
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 30
-        is_tax_unit_head: true
-        employment_income: 95_000
-    tax_units:
-      tax_unit:
-        members: [person1]
-    households:
-      household:
-        members: [person1]
-        state_code: SC
-  output:
-    # AGI $95k = phase-out end ($40k + $55k)
-    # Phase-out fraction = $55,000 / $55,000 = 1.0
-    # SCIAD = $15,000 * (1 - 1) = $0
-    sc_sciad: 0
-
-- name: Case 17, SCIAD one dollar below phase-out end (single).
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 30
-        is_tax_unit_head: true
-        employment_income: 94_999
-    tax_units:
-      tax_unit:
-        members: [person1]
-    households:
-      household:
-        members: [person1]
-        state_code: SC
-  output:
-    # AGI $94,999, excess = $94,999 - $40,000 = $54,999
-    # Phase-out fraction = $54,999 / $55,000 = 0.9999818
-    # Raw SCIAD = $15,000 * (1 - 0.9999818) = $0.27
-    # Rounded down to nearest $10: $0
-    sc_sciad: 0
-
-- name: Case 18, SCIAD at exactly phase-out start (joint).
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 35
-        is_tax_unit_head: true
-        employment_income: 50_000
-      person2:
-        age: 33
-        is_tax_unit_spouse: true
-        employment_income: 30_000
-    tax_units:
-      tax_unit:
-        members: [person1, person2]
-        filing_status: JOINT
-    households:
-      household:
-        members: [person1, person2]
-        state_code: SC
-  output:
-    # AGI $80k = phase-out start for joint, full SCIAD
-    sc_sciad: 30_000
-
-- name: Case 19, SCIAD at exactly phase-out end (joint).
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 35
-        is_tax_unit_head: true
-        employment_income: 100_000
-      person2:
-        age: 33
-        is_tax_unit_spouse: true
-        employment_income: 90_000
-    tax_units:
-      tax_unit:
-        members: [person1, person2]
-        filing_status: JOINT
-    households:
-      household:
-        members: [person1, person2]
-        state_code: SC
-  output:
-    # AGI $190k = phase-out end ($80k + $110k)
-    # SCIAD fully phased out
-    sc_sciad: 0
-
-- name: Case 20, SCIAD at exactly phase-out start (HOH).
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 35
-        is_tax_unit_head: true
-        employment_income: 60_000
-      person2:
-        age: 10
-        is_tax_unit_dependent: true
-    tax_units:
-      tax_unit:
-        members: [person1, person2]
-        filing_status: HEAD_OF_HOUSEHOLD
-    households:
-      household:
-        members: [person1, person2]
-        state_code: SC
-  output:
-    # AGI $60k = phase-out start for HOH, full SCIAD
-    sc_sciad: 22_500
-
-- name: Case 21, SCIAD at exactly phase-out end (HOH).
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 35
-        is_tax_unit_head: true
-        employment_income: 142_500
-      person2:
-        age: 10
-        is_tax_unit_dependent: true
-    tax_units:
-      tax_unit:
-        members: [person1, person2]
-        filing_status: HEAD_OF_HOUSEHOLD
-    households:
-      household:
-        members: [person1, person2]
-        state_code: SC
-  output:
-    # AGI $142,500 = phase-out end ($60k + $82,500)
-    # SCIAD fully phased out
-    sc_sciad: 0
-
-# Filing Status Tests
-
-- name: Case 22, SCIAD for married filing separately.
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 35
-        is_tax_unit_head: true
-        employment_income: 35_000
-    tax_units:
-      tax_unit:
-        members: [person1]
-        filing_status: SEPARATE
-    households:
-      household:
-        members: [person1]
-        state_code: SC
-  output:
-    # AGI $35k < phase-out start $40k for SEPARATE
-    # Full SCIAD = $15,000
-    sc_sciad: 15_000
-
-- name: Case 23, SCIAD for separate filer in phase-out range.
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 35
-        is_tax_unit_head: true
-        employment_income: 67_500
-    tax_units:
-      tax_unit:
-        members: [person1]
-        filing_status: SEPARATE
-    households:
-      household:
-        members: [person1]
-        state_code: SC
-  output:
-    # AGI $67,500, phase-out start $40k, width $55k
-    # Excess = $67,500 - $40,000 = $27,500
-    # Phase-out fraction = $27,500 / $55,000 = 0.5
-    # SCIAD = $15,000 * (1 - 0.5) = $7,500
-    sc_sciad: 7_500
-
-- name: Case 24, SCIAD fully phased out for separate filer.
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 35
-        is_tax_unit_head: true
-        employment_income: 100_000
-    tax_units:
-      tax_unit:
-        members: [person1]
-        filing_status: SEPARATE
-    households:
-      household:
-        members: [person1]
-        state_code: SC
-  output:
-    # AGI $100k > phase-out end $95k ($40k + $55k)
-    # SCIAD fully phased out
-    sc_sciad: 0
-
-- name: Case 25, SCIAD for surviving spouse below phase-out.
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 35
-        is_tax_unit_head: true
-        employment_income: 75_000
-      person2:
-        age: 10
-        is_tax_unit_dependent: true
-    tax_units:
-      tax_unit:
-        members: [person1, person2]
-        filing_status: SURVIVING_SPOUSE
-    households:
-      household:
-        members: [person1, person2]
-        state_code: SC
-  output:
-    # AGI $75k < phase-out start $80k for SURVIVING_SPOUSE
-    # Full SCIAD = $30,000
-    sc_sciad: 30_000
-
-- name: Case 26, SCIAD for surviving spouse in phase-out range.
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 35
-        is_tax_unit_head: true
-        employment_income: 135_000
-      person2:
-        age: 10
-        is_tax_unit_dependent: true
-    tax_units:
-      tax_unit:
-        members: [person1, person2]
-        filing_status: SURVIVING_SPOUSE
-    households:
-      household:
-        members: [person1, person2]
-        state_code: SC
-  output:
-    # AGI $135k, phase-out start $80k, width $110k
-    # Excess = $135,000 - $80,000 = $55,000
-    # Phase-out fraction = $55,000 / $110,000 = 0.5
-    # SCIAD = $30,000 * (1 - 0.5) = $15,000
-    sc_sciad: 15_000
-
-- name: Case 27, SCIAD fully phased out for surviving spouse.
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 35
-        is_tax_unit_head: true
-        employment_income: 200_000
-      person2:
-        age: 10
-        is_tax_unit_dependent: true
-    tax_units:
-      tax_unit:
-        members: [person1, person2]
-        filing_status: SURVIVING_SPOUSE
-    households:
-      household:
-        members: [person1, person2]
-        state_code: SC
-  output:
-    # AGI $200k > phase-out end $190k ($80k + $110k)
-    # SCIAD fully phased out
-    sc_sciad: 0
-
-# Standard/Itemized Deduction Elimination Tests
-
-- name: Case 28, federal standard deduction ignored - uses SCIAD not federal deductions.
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 30
-        is_tax_unit_head: true
-        employment_income: 50_000
-    tax_units:
-      tax_unit:
-        members: [person1]
-    households:
-      household:
-        members: [person1]
-        state_code: SC
-  output:
-    # AGI = $50,000
-    # Federal standard deduction would be ~$15,200 (2026)
-    # But H.4216 ignores federal deductions and uses SCIAD instead
-    # SCIAD at $50k AGI: excess = $50k - $40k = $10k
-    # Phase-out fraction = $10k / $55k = 0.18182
-    # Raw SCIAD = $15,000 * (1 - 0.18182) = $12,272.73
-    # Rounded down to nearest $10: $12,270
-    # SC taxable income = $50,000 - $12,270 = $37,730
-    sc_sciad: 12_270
-    sc_taxable_income: 37_730
-
-- name: Case 29, high income with no SCIAD (fully phased out).
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 30
-        is_tax_unit_head: true
-        employment_income: 150_000
-    tax_units:
-      tax_unit:
-        members: [person1]
-    households:
-      household:
-        members: [person1]
-        state_code: SC
-  output:
-    # AGI = $150,000
-    # H.4216 starts from AGI (ignores federal standard deduction)
-    # SCIAD at $150k AGI: AGI > phase-out end ($95k), SCIAD = $0
-    # SC taxable income = AGI - SCIAD = $150,000
-    sc_sciad: 0
-    sc_taxable_income: 150_000
-
-# Rate Bracket Boundary Tests
-
-- name: Case 30, taxable income exactly at $30k bracket boundary.
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 30
-        is_tax_unit_head: true
-    tax_units:
-      tax_unit:
-        members: [person1]
-        adjusted_gross_income: 30_000
-        sc_additions: 0
-        sc_subtractions: 0
-        sc_sciad: 0
-    households:
-      household:
-        members: [person1]
-        state_code: SC
-  output:
-    # SC taxable income = $30,000 (directly set via AGI with no deductions)
-    # Tax = $30,000 * 1.99% = $597
-    # All income in first bracket only
-    sc_taxable_income: 30_000
-    sc_income_tax_before_non_refundable_credits: 597
-
-- name: Case 31, taxable income one dollar above $30k bracket.
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 30
-        is_tax_unit_head: true
-    tax_units:
-      tax_unit:
-        members: [person1]
-        adjusted_gross_income: 30_001
-        sc_additions: 0
-        sc_subtractions: 0
-        sc_sciad: 0
-    households:
-      household:
-        members: [person1]
-        state_code: SC
-  output:
-    # SC taxable income = $30,001
-    # Tax = $30,000 * 1.99% + $1 * 5.21% = $597 + $0.0521 = $597.05
-    sc_taxable_income: 30_001
-    sc_income_tax_before_non_refundable_credits: 597.1
-
-- name: Case 32, high income tax calculation.
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 30
-        is_tax_unit_head: true
-        employment_income: 125_000
-    tax_units:
-      tax_unit:
-        members: [person1]
-    households:
-      household:
-        members: [person1]
-        state_code: SC
-  output:
-    # AGI $125k, SCIAD $0 (fully phased out above $95k)
-    # SC taxable income = $125k
-    # Tax = $30k * 1.99% + $95k * 5.21% = $597 + $4,949.50 = $5,546.50
-    sc_income_tax_before_non_refundable_credits: 5_546.5
-
-# Zero/Low Income Edge Cases
-
-- name: Case 33, zero income results in zero tax.
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 30
-        is_tax_unit_head: true
-        employment_income: 0
-    tax_units:
-      tax_unit:
-        members: [person1]
-    households:
-      household:
-        members: [person1]
-        state_code: SC
-  output:
-    sc_sciad: 15_000
-    sc_taxable_income: 0
-    sc_income_tax_before_non_refundable_credits: 0
-
-- name: Case 34, income below SCIAD results in zero taxable income.
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 30
-        is_tax_unit_head: true
-        employment_income: 10_000
-    tax_units:
-      tax_unit:
-        members: [person1]
-    households:
-      household:
-        members: [person1]
-        state_code: SC
-  output:
-    # AGI $10k < SCIAD $15k
-    # SC taxable income = max(0, $10k - $15k) = $0
-    sc_sciad: 15_000
-    sc_taxable_income: 0
-    sc_income_tax_before_non_refundable_credits: 0
-
-# Negative AGI Edge Case
-
-- name: Case 35, negative AGI with self-employment loss.
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 30
-        is_tax_unit_head: true
-        self_employment_income: -20_000
-    tax_units:
-      tax_unit:
-        members: [person1]
-    households:
-      household:
-        members: [person1]
-        state_code: SC
-  output:
-    # AGI is negative from SE loss
-    # SCIAD: excess_agi = max_(negative - $40k, 0) = 0, full SCIAD = $15,000
-    # SC taxable income = max_(0, negative - $15,000) = $0
-    sc_sciad: 15_000
-    sc_taxable_income: 0
-    sc_income_tax_before_non_refundable_credits: 0
-    sc_eitc: 0
-
-# SC Subtractions Interaction
-# Note: sc_additions (QBI addback, SALT addback) are excluded from the
-# reform formula because it starts from AGI where those federal deductions
-# were never taken. Only sc_subtractions (retirement, military) apply.
-
-- name: Case 36, SC subtractions reduce taxable income (additions excluded).
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 30
-        is_tax_unit_head: true
-    tax_units:
-      tax_unit:
-        members: [person1]
-        adjusted_gross_income: 50_000
-        sc_additions: 5_000
-        sc_subtractions: 2_000
-        sc_sciad: 0
-    households:
-      household:
-        members: [person1]
-        state_code: SC
-  output:
-    # sc_additions ignored (AGI base already excludes federal deductions)
-    # SC taxable income = $50,000 - $2,000 - $0 = $48,000
-    # Tax = $30k * 1.99% + $18k * 5.21% = $597 + $937.80 = $1,534.80
-    sc_taxable_income: 48_000
-    sc_income_tax_before_non_refundable_credits: 1_534.8
-
-# Joint Filer SCIAD Greater Than AGI
-
-- name: Case 37, joint filer SCIAD exceeds AGI.
-  period: 2026
-  absolute_error_margin: 0.1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 35
-        is_tax_unit_head: true
-        employment_income: 15_000
-      person2:
-        age: 33
-        is_tax_unit_spouse: true
-        employment_income: 5_000
-    tax_units:
-      tax_unit:
-        members: [person1, person2]
-        filing_status: JOINT
-    households:
-      household:
-        members: [person1, person2]
-        state_code: SC
-  output:
-    # AGI = $20,000 < phase-out start $80k
-    # Full SCIAD = $30,000
-    # SC taxable income = max(0, $20,000 - $30,000) = $0
-    sc_sciad: 30_000
-    sc_taxable_income: 0
-    sc_income_tax_before_non_refundable_credits: 0
-
-# End-to-End Tax Calculation with EITC
-
-- name: Case 38, end-to-end tax with EITC and all components.
-  period: 2026
-  absolute_error_margin: 1
-  reforms: policyengine_us.reforms.states.sc.h4216.sc_h4216.sc_h4216
-  input:
-    gov.contrib.states.sc.h4216.in_effect: true
-    people:
-      person1:
-        age: 30
-        is_tax_unit_head: true
-    tax_units:
-      tax_unit:
-        members: [person1]
-        adjusted_gross_income: 50_000
-        eitc: 500
-        sc_additions: 0
-        sc_subtractions: 0
-    households:
-      household:
-        members: [person1]
-        state_code: SC
-  output:
-    # EITC: min($500 * 1.25, $200) = min($625, $200) = $200
-    sc_eitc: 200
-    # SCIAD for SINGLE: AGI $50k, phase-out start $40k, width $55k
-    # Excess = $10k, fraction = $10k/$55k = 0.18182
-    # Raw SCIAD = $15,000 * (1 - 0.18182) = $12,272.73
-    # Rounded down to nearest $10: $12,270
-    sc_sciad: 12_270
-    # SC taxable income = $50,000 - $12,270 = $37,730
-    sc_taxable_income: 37_730
-    # Tax = $30k * 1.99% + $7,730 * 5.21% = $597 + $402.73 = $999.73
-    sc_income_tax_before_non_refundable_credits: 1_000
diff --git a/policyengine_us/variables/gov/states/sc/tax/income/credits/eitc/sc_eitc.py b/policyengine_us/variables/gov/states/sc/tax/income/credits/eitc/sc_eitc.py
index 8e5ea5d3b07..4d5bd51f565 100644
--- a/policyengine_us/variables/gov/states/sc/tax/income/credits/eitc/sc_eitc.py
+++ b/policyengine_us/variables/gov/states/sc/tax/income/credits/eitc/sc_eitc.py
@@ -7,10 +7,15 @@ class sc_eitc(Variable):
     label = "South Carolina EITC"
     unit = USD
     definition_period = YEAR
-    reference = "https://dor.sc.gov/forms-site/Forms/TC60_2021.pdf"
+    reference = (
+        "https://dor.sc.gov/forms-site/Forms/TC60_2021.pdf",
+        "https://www.scstatehouse.gov/sess126_2025-2026/bills/4216.htm",
+    )
     defined_for = StateCode.SC
 
     def formula(tax_unit, period, parameters):
         federal_eitc = tax_unit("eitc", period)
-        rate = parameters(period).gov.states.sc.tax.income.credits.eitc.rate
-        return np.round(federal_eitc * rate, 1)
+        p = parameters(period).gov.states.sc.tax.income.credits.eitc
+        uncapped = np.round(federal_eitc * p.rate, 1)
+        # Apply cap (infinite before 2026, $200 from 2026+)
+        return min_(uncapped, p.max)
diff --git a/policyengine_us/variables/gov/states/sc/tax/income/deductions/sciad/sc_sciad.py b/policyengine_us/variables/gov/states/sc/tax/income/deductions/sciad/sc_sciad.py
new file mode 100644
index 00000000000..b5350fd49ab
--- /dev/null
+++ b/policyengine_us/variables/gov/states/sc/tax/income/deductions/sciad/sc_sciad.py
@@ -0,0 +1,34 @@
+from policyengine_us.model_api import *
+
+
+class sc_sciad(Variable):
+    value_type = float
+    entity = TaxUnit
+    label = "South Carolina Income Adjusted Deduction (SCIAD)"
+    unit = USD
+    definition_period = YEAR
+    reference = ("https://www.scstatehouse.gov/sess126_2025-2026/bills/4216.htm",)
+    defined_for = StateCode.SC
+
+    def formula(tax_unit, period, parameters):
+        p = parameters(period).gov.states.sc.tax.income.deductions.sciad
+        # SCIAD only exists starting 2026
+        if not p.in_effect:
+            return tax_unit("adjusted_gross_income", period) * 0
+        filing_status = tax_unit("filing_status", period)
+        # Get the base amount by filing status
+        base_amount = p.amount[filing_status]
+        # Get federal AGI for phase-out calculation
+        agi = tax_unit("adjusted_gross_income", period)
+        # Get phase-out parameters by filing status
+        phase_out_start = p.phase_out.start[filing_status]
+        phase_out_width = p.phase_out.width[filing_status]
+        # Calculate phase-out fraction
+        # fraction = (AGI - start) / width
+        excess_agi = max_(0, agi - phase_out_start)
+        phase_out_fraction = min_(1, excess_agi / phase_out_width)
+        # Calculate reduction
+        reduction = base_amount * phase_out_fraction
+        # Round reduction down to nearest $10
+        reduction_rounded = np.floor(reduction / 10) * 10
+        return max_(0, base_amount - reduction_rounded)
diff --git a/policyengine_us/variables/gov/states/sc/tax/income/sc_taxable_income.py b/policyengine_us/variables/gov/states/sc/tax/income/sc_taxable_income.py
index 433fc8d0d16..3bba844b471 100644
--- a/policyengine_us/variables/gov/states/sc/tax/income/sc_taxable_income.py
+++ b/policyengine_us/variables/gov/states/sc/tax/income/sc_taxable_income.py
@@ -8,10 +8,23 @@ class sc_taxable_income(Variable):
     defined_for = StateCode.SC
     unit = USD
     definition_period = YEAR
-    reference = "https://dor.sc.gov/forms-site/Forms/IITPacket_2022.pdf#page=33"
+    reference = (
+        "https://dor.sc.gov/forms-site/Forms/IITPacket_2022.pdf#page=33",
+        "https://www.scstatehouse.gov/sess126_2025-2026/bills/4216.htm",
+    )
 
     def formula(tax_unit, period, parameters):
-        taxable_income = tax_unit("taxable_income", period)
-        additions = tax_unit("sc_additions", period)
+        p = parameters(period).gov.states.sc.tax.income.deductions.sciad
         subtractions = tax_unit("sc_subtractions", period)
-        return max_(0, taxable_income + additions - subtractions)
+
+        if p.in_effect:
+            # H4216: Start from AGI (SC ignores federal std/itemized deductions)
+            # Additions are not needed since they correct for federal deductions
+            # that are no longer relevant when starting from AGI
+            agi = tax_unit("adjusted_gross_income", period)
+            return max_(0, agi - subtractions)
+        else:
+            # Traditional calculation from federal taxable income
+            taxable_income = tax_unit("taxable_income", period)
+            additions = tax_unit("sc_additions", period)
+            return max_(0, taxable_income + additions - subtractions)