diff --git a/changelog.d/ga-sb520-tax-reform.added.md b/changelog.d/ga-sb520-tax-reform.added.md
new file mode 100644
index 00000000000..5fc01128936
--- /dev/null
+++ b/changelog.d/ga-sb520-tax-reform.added.md
@@ -0,0 +1 @@
+Added Georgia SB 520 contributed reform implementing progressive income tax brackets (2027), increased standard deduction with phase-out, enhanced child tax credit ($1,250 refundable), and new Georgia EITC (20% of federal).
diff --git a/policyengine_us/parameters/gov/contrib/states/ga/sb520/brackets/head_of_household.yaml b/policyengine_us/parameters/gov/contrib/states/ga/sb520/brackets/head_of_household.yaml
new file mode 100644
index 00000000000..fabed9f0f60
--- /dev/null
+++ b/policyengine_us/parameters/gov/contrib/states/ga/sb520/brackets/head_of_household.yaml
@@ -0,0 +1,24 @@
+description: Georgia SB 520 taxes the personal income of head of household filers at these progressive rates.
+
+metadata:
+  type: marginal_rate
+  threshold_unit: currency-USD
+  rate_unit: /1
+  label: Georgia SB 520 income tax rate head of household filers
+  reference:
+    - title: Georgia SB 520 Section 1 - 48-7-20(a.1)(2)
+      href: https://www.legis.ga.gov/api/legislation/document/20252026/242809#page=3
+
+brackets:
+  - threshold:
+      2027-01-01: 0
+    rate:
+      2027-01-01: 0.02
+  - threshold:
+      2027-01-01: 15_000
+    rate:
+      2027-01-01: 0.04
+  - threshold:
+      2027-01-01: 30_000
+    rate:
+      2027-01-01: 0.06
diff --git a/policyengine_us/parameters/gov/contrib/states/ga/sb520/brackets/in_effect.yaml b/policyengine_us/parameters/gov/contrib/states/ga/sb520/brackets/in_effect.yaml
new file mode 100644
index 00000000000..ee87f581209
--- /dev/null
+++ b/policyengine_us/parameters/gov/contrib/states/ga/sb520/brackets/in_effect.yaml
@@ -0,0 +1,12 @@
+description: Georgia applies SB 520 2027 provisions (progressive income tax brackets).
+
+values:
+  0000-01-01: false
+
+metadata:
+  unit: bool
+  period: year
+  label: Georgia SB 520 2027 provisions in effect
+  reference:
+    - title: Georgia SB 520 Section 1
+      href: https://www.legis.ga.gov/api/legislation/document/20252026/242809#page=2
diff --git a/policyengine_us/parameters/gov/contrib/states/ga/sb520/brackets/joint.yaml b/policyengine_us/parameters/gov/contrib/states/ga/sb520/brackets/joint.yaml
new file mode 100644
index 00000000000..f3d4f1b6187
--- /dev/null
+++ b/policyengine_us/parameters/gov/contrib/states/ga/sb520/brackets/joint.yaml
@@ -0,0 +1,24 @@
+description: Georgia SB 520 taxes the personal income of joint filers at these progressive rates.
+
+metadata:
+  type: marginal_rate
+  threshold_unit: currency-USD
+  rate_unit: /1
+  label: Georgia SB 520 income tax rate joint filers
+  reference:
+    - title: Georgia SB 520 Section 1 - 48-7-20(a.1)(1)
+      href: https://www.legis.ga.gov/api/legislation/document/20252026/242809#page=3
+
+brackets:
+  - threshold:
+      2027-01-01: 0
+    rate:
+      2027-01-01: 0.02
+  - threshold:
+      2027-01-01: 30_000
+    rate:
+      2027-01-01: 0.04
+  - threshold:
+      2027-01-01: 60_000
+    rate:
+      2027-01-01: 0.06
diff --git a/policyengine_us/parameters/gov/contrib/states/ga/sb520/brackets/separate.yaml b/policyengine_us/parameters/gov/contrib/states/ga/sb520/brackets/separate.yaml
new file mode 100644
index 00000000000..3971f2317ee
--- /dev/null
+++ b/policyengine_us/parameters/gov/contrib/states/ga/sb520/brackets/separate.yaml
@@ -0,0 +1,24 @@
+description: Georgia SB 520 taxes the personal income of married filing separately filers at these progressive rates.
+
+metadata:
+  type: marginal_rate
+  threshold_unit: currency-USD
+  rate_unit: /1
+  label: Georgia SB 520 income tax rate married filing separately filers
+  reference:
+    - title: Georgia SB 520 Section 1 - 48-7-20(a.1)(2)
+      href: https://www.legis.ga.gov/api/legislation/document/20252026/242809#page=3
+
+brackets:
+  - threshold:
+      2027-01-01: 0
+    rate:
+      2027-01-01: 0.02
+  - threshold:
+      2027-01-01: 15_000
+    rate:
+      2027-01-01: 0.04
+  - threshold:
+      2027-01-01: 30_000
+    rate:
+      2027-01-01: 0.06
diff --git a/policyengine_us/parameters/gov/contrib/states/ga/sb520/brackets/single.yaml b/policyengine_us/parameters/gov/contrib/states/ga/sb520/brackets/single.yaml
new file mode 100644
index 00000000000..5f5784913f7
--- /dev/null
+++ b/policyengine_us/parameters/gov/contrib/states/ga/sb520/brackets/single.yaml
@@ -0,0 +1,24 @@
+description: Georgia SB 520 taxes the personal income of single filers at these progressive rates.
+
+metadata:
+  type: marginal_rate
+  threshold_unit: currency-USD
+  rate_unit: /1
+  label: Georgia SB 520 income tax rate single filers
+  reference:
+    - title: Georgia SB 520 Section 1 - 48-7-20(a.1)(2)
+      href: https://www.legis.ga.gov/api/legislation/document/20252026/242809#page=3
+
+brackets:
+  - threshold:
+      2027-01-01: 0
+    rate:
+      2027-01-01: 0.02
+  - threshold:
+      2027-01-01: 15_000
+    rate:
+      2027-01-01: 0.04
+  - threshold:
+      2027-01-01: 30_000
+    rate:
+      2027-01-01: 0.06
diff --git a/policyengine_us/parameters/gov/contrib/states/ga/sb520/brackets/surviving_spouse.yaml b/policyengine_us/parameters/gov/contrib/states/ga/sb520/brackets/surviving_spouse.yaml
new file mode 100644
index 00000000000..48f03f4dc8a
--- /dev/null
+++ b/policyengine_us/parameters/gov/contrib/states/ga/sb520/brackets/surviving_spouse.yaml
@@ -0,0 +1,24 @@
+description: Georgia SB 520 taxes the personal income of surviving spouse filers at these progressive rates.
+
+metadata:
+  type: marginal_rate
+  threshold_unit: currency-USD
+  rate_unit: /1
+  label: Georgia SB 520 income tax rate surviving spouse filers
+  reference:
+    - title: Georgia SB 520 Section 1 - 48-7-20(a.1)(1)
+      href: https://www.legis.ga.gov/api/legislation/document/20252026/242809#page=3
+
+brackets:
+  - threshold:
+      2027-01-01: 0
+    rate:
+      2027-01-01: 0.02
+  - threshold:
+      2027-01-01: 30_000
+    rate:
+      2027-01-01: 0.04
+  - threshold:
+      2027-01-01: 60_000
+    rate:
+      2027-01-01: 0.06
diff --git a/policyengine_us/parameters/gov/contrib/states/ga/sb520/credits/ctc/amount.yaml b/policyengine_us/parameters/gov/contrib/states/ga/sb520/credits/ctc/amount.yaml
new file mode 100644
index 00000000000..1b323db0b0e
--- /dev/null
+++ b/policyengine_us/parameters/gov/contrib/states/ga/sb520/credits/ctc/amount.yaml
@@ -0,0 +1,12 @@
+description: Georgia SB 520 provides this child tax credit amount for each qualifying child.
+
+values:
+  2026-01-01: 1_250
+
+metadata:
+  unit: currency-USD
+  period: year
+  label: Georgia SB 520 child tax credit amount
+  reference:
+    - title: Georgia SB 520 Section 6 - 48-7-29.27(b)(1)
+      href: https://www.legis.ga.gov/api/legislation/document/20252026/242809#page=6
diff --git a/policyengine_us/parameters/gov/contrib/states/ga/sb520/credits/eitc/match.yaml b/policyengine_us/parameters/gov/contrib/states/ga/sb520/credits/eitc/match.yaml
new file mode 100644
index 00000000000..aec33b0777b
--- /dev/null
+++ b/policyengine_us/parameters/gov/contrib/states/ga/sb520/credits/eitc/match.yaml
@@ -0,0 +1,12 @@
+description: Georgia SB 520 provides a state EITC equal to this percentage of the federal EITC.
+
+values:
+  2026-01-01: 0.2
+
+metadata:
+  unit: /1
+  period: year
+  label: Georgia SB 520 EITC match rate
+  reference:
+    - title: Georgia SB 520 Section 7 - 48-7-29.29(a)
+      href: https://www.legis.ga.gov/api/legislation/document/20252026/242809#page=6
diff --git a/policyengine_us/parameters/gov/contrib/states/ga/sb520/deductions/standard/amount.yaml b/policyengine_us/parameters/gov/contrib/states/ga/sb520/deductions/standard/amount.yaml
new file mode 100644
index 00000000000..b9176bd0dc2
--- /dev/null
+++ b/policyengine_us/parameters/gov/contrib/states/ga/sb520/deductions/standard/amount.yaml
@@ -0,0 +1,22 @@
+description: Georgia SB 520 provides filers a standard deduction of this amount, depending on filing status.
+
+metadata:
+  label: Georgia SB 520 standard deduction amount
+  period: year
+  unit: currency-USD
+  breakdown:
+    - filing_status
+  reference:
+    - title: Georgia SB 520 Section 4 - 48-7-27(a)(1)
+      href: https://www.legis.ga.gov/api/legislation/document/20252026/242809#page=5
+
+JOINT:
+  2026-01-01: 34_000
+HEAD_OF_HOUSEHOLD:
+  2026-01-01: 17_000
+SINGLE:
+  2026-01-01: 17_000
+SEPARATE:
+  2026-01-01: 17_000
+SURVIVING_SPOUSE:
+  2026-01-01: 34_000
diff --git a/policyengine_us/parameters/gov/contrib/states/ga/sb520/deductions/standard/phase_out/rate.yaml b/policyengine_us/parameters/gov/contrib/states/ga/sb520/deductions/standard/phase_out/rate.yaml
new file mode 100644
index 00000000000..61a0e3193cc
--- /dev/null
+++ b/policyengine_us/parameters/gov/contrib/states/ga/sb520/deductions/standard/phase_out/rate.yaml
@@ -0,0 +1,12 @@
+description: Georgia SB 520 reduces the standard deduction by this rate for each dollar of federal AGI above the threshold.
+
+values:
+  2026-01-01: 0.25
+
+metadata:
+  label: Georgia SB 520 standard deduction phase-out rate
+  period: year
+  unit: /1
+  reference:
+    - title: Georgia SB 520 Section 4 - 48-7-27(a)(1)(C)
+      href: https://www.legis.ga.gov/api/legislation/document/20252026/242809#page=5
diff --git a/policyengine_us/parameters/gov/contrib/states/ga/sb520/deductions/standard/phase_out/threshold.yaml b/policyengine_us/parameters/gov/contrib/states/ga/sb520/deductions/standard/phase_out/threshold.yaml
new file mode 100644
index 00000000000..41dff3a4c68
--- /dev/null
+++ b/policyengine_us/parameters/gov/contrib/states/ga/sb520/deductions/standard/phase_out/threshold.yaml
@@ -0,0 +1,22 @@
+description: Georgia SB 520 phases out the standard deduction for filers with federal AGI above this threshold.
+
+metadata:
+  label: Georgia SB 520 standard deduction phase-out threshold
+  period: year
+  unit: currency-USD
+  breakdown:
+    - filing_status
+  reference:
+    - title: Georgia SB 520 Section 4 - 48-7-27(a)(1)(C)
+      href: https://www.legis.ga.gov/api/legislation/document/20252026/242809#page=5
+
+JOINT:
+  2026-01-01: 280_000
+HEAD_OF_HOUSEHOLD:
+  2026-01-01: 140_000
+SINGLE:
+  2026-01-01: 140_000
+SEPARATE:
+  2026-01-01: 140_000
+SURVIVING_SPOUSE:
+  2026-01-01: 280_000
diff --git a/policyengine_us/parameters/gov/contrib/states/ga/sb520/in_effect.yaml b/policyengine_us/parameters/gov/contrib/states/ga/sb520/in_effect.yaml
new file mode 100644
index 00000000000..c72a791bd93
--- /dev/null
+++ b/policyengine_us/parameters/gov/contrib/states/ga/sb520/in_effect.yaml
@@ -0,0 +1,12 @@
+description: Georgia applies SB 520 2026 provisions (standard deduction increase, child tax credit increase, state EITC).
+
+values:
+  0000-01-01: false
+
+metadata:
+  unit: bool
+  period: year
+  label: Georgia SB 520 2026 provisions in effect
+  reference:
+    - title: Georgia SB 520 Sections 4, 6, 7
+      href: https://www.legis.ga.gov/api/legislation/document/20252026/242809#page=1
diff --git a/policyengine_us/reforms/reforms.py b/policyengine_us/reforms/reforms.py
index ed587c8cc78..3070e9395e9 100644
--- a/policyengine_us/reforms/reforms.py
+++ b/policyengine_us/reforms/reforms.py
@@ -179,6 +179,9 @@
 )
 
 
+from .states.ga.sb520 import (
+    create_ga_sb520_reform,
+)
 from policyengine_core.reforms import Reform
 import warnings
 
@@ -341,6 +344,7 @@ def create_structural_reforms_from_parameters(parameters, period):
     ct_sb100 = create_ct_sb100_reform(parameters, period)
     ct_tax_rebate_2026 = create_ct_tax_rebate_2026_reform(parameters, period)
     ct_hb5009 = create_ct_hb5009_reform(parameters, period)
+    ga_sb520 = create_ga_sb520_reform(parameters, period)
     watca = create_watca_reform(parameters, period)
 
     reforms = [
@@ -422,6 +426,7 @@ def create_structural_reforms_from_parameters(parameters, period):
         ct_hb5009,
         ct_sb100,
         ct_tax_rebate_2026,
+        ga_sb520,
         watca,
     ]
     reforms = tuple(filter(lambda x: x is not None, reforms))
diff --git a/policyengine_us/reforms/states/ga/sb520/__init__.py b/policyengine_us/reforms/states/ga/sb520/__init__.py
new file mode 100644
index 00000000000..46c38ef84a0
--- /dev/null
+++ b/policyengine_us/reforms/states/ga/sb520/__init__.py
@@ -0,0 +1,3 @@
+from .ga_sb520_reform import ga_sb520, create_ga_sb520_reform
+
+__all__ = ["ga_sb520", "create_ga_sb520_reform"]
diff --git a/policyengine_us/reforms/states/ga/sb520/ga_sb520_reform.py b/policyengine_us/reforms/states/ga/sb520/ga_sb520_reform.py
new file mode 100644
index 00000000000..c6b4cfb0fc5
--- /dev/null
+++ b/policyengine_us/reforms/states/ga/sb520/ga_sb520_reform.py
@@ -0,0 +1,264 @@
+from policyengine_us.model_api import *
+from policyengine_core.periods import period as period_
+
+
+def create_ga_sb520() -> Reform:
+    class ga_standard_deduction(Variable):
+        value_type = float
+        entity = TaxUnit
+        label = "Georgia standard deduction"
+        unit = USD
+        definition_period = YEAR
+        reference = (
+            "https://www.legis.ga.gov/api/legislation/document/20252026/242809#page=5",
+        )
+        defined_for = StateCode.GA
+
+        def formula(tax_unit, period, parameters):
+            p = parameters(period).gov.states.ga.tax.income.deductions.standard
+            p_sb520 = parameters(period).gov.contrib.states.ga.sb520
+            filing_status = tax_unit("filing_status", period)
+
+            sb520_active = p_sb520.in_effect
+
+            sb520_base = p_sb520.deductions.standard.amount[filing_status]
+            sb520_threshold = p_sb520.deductions.standard.phase_out.threshold[
+                filing_status
+            ]
+            sb520_rate = p_sb520.deductions.standard.phase_out.rate
+
+            agi = tax_unit("adjusted_gross_income", period)
+            excess_income = max_(agi - sb520_threshold, 0)
+            phase_out_amount = excess_income * sb520_rate
+            sb520_deduction = max_(sb520_base - phase_out_amount, 0)
+
+            baseline_base = p.amount[filing_status]
+            if p.applies:
+                additional_standard = tax_unit(
+                    "ga_additional_standard_deduction", period
+                )
+                baseline_deduction = baseline_base + additional_standard
+            else:
+                baseline_deduction = baseline_base
+
+            return where(sb520_active, sb520_deduction, baseline_deduction)
+
+    class ga_deductions(Variable):
+        value_type = float
+        entity = TaxUnit
+        label = "Georgia deductions"
+        unit = USD
+        definition_period = YEAR
+        reference = (
+            # SB 520 Section 4 eliminates itemized deduction option
+            "https://www.legis.ga.gov/api/legislation/document/20252026/242809#page=5",
+        )
+        defined_for = StateCode.GA
+
+        def formula(tax_unit, period, parameters):
+            p_sb520 = parameters(period).gov.contrib.states.ga.sb520
+
+            sb520_active = p_sb520.in_effect
+
+            # SB 520 Section 4 eliminates the option to itemize - standard deduction only
+            sb520_deduction = tax_unit("ga_standard_deduction", period)
+
+            # Baseline: itemize if federal itemizes
+            itemizes = tax_unit("tax_unit_itemizes", period)
+            sd = tax_unit("ga_standard_deduction", period)
+            p = parameters(period).gov.irs.deductions
+            itemized = add(tax_unit, period, p.itemized_deductions)
+            baseline_deduction = where(itemizes, itemized, sd)
+
+            return where(sb520_active, sb520_deduction, baseline_deduction)
+
+    class ga_ctc(Variable):
+        value_type = float
+        entity = TaxUnit
+        label = "Georgia Child Tax Credit"
+        unit = USD
+        definition_period = YEAR
+        defined_for = StateCode.GA
+        reference = (
+            "https://www.legis.ga.gov/api/legislation/document/20252026/242809#page=6",
+        )
+
+        def formula(tax_unit, period, parameters):
+            p = parameters(period).gov.states.ga.tax.income.credits.ctc
+            p_sb520 = parameters(period).gov.contrib.states.ga.sb520
+
+            sb520_active = p_sb520.in_effect
+
+            person = tax_unit.members
+            age = person("age", period)
+            ctc_eligible_child = person("ctc_qualifying_child", period)
+            # SB 520 preserves baseline GA CTC age threshold (under 6)
+            ga_child_age_eligible = age < p.age_threshold
+            eligible_children = tax_unit.sum(ctc_eligible_child & ga_child_age_eligible)
+
+            sb520_amount = p_sb520.credits.ctc.amount
+            baseline_amount = p.amount
+
+            amount_per_child = where(sb520_active, sb520_amount, baseline_amount)
+            return eligible_children * amount_per_child
+
+    class ga_eitc(Variable):
+        value_type = float
+        entity = TaxUnit
+        label = "Georgia Earned Income Tax Credit"
+        unit = USD
+        definition_period = YEAR
+        defined_for = StateCode.GA
+        reference = (
+            "https://www.legis.ga.gov/api/legislation/document/20252026/242809#page=6",
+        )
+
+        def formula(tax_unit, period, parameters):
+            p_sb520 = parameters(period).gov.contrib.states.ga.sb520
+
+            sb520_active = p_sb520.in_effect
+
+            federal_eitc = tax_unit("eitc", period)
+            match_rate = p_sb520.credits.eitc.match
+
+            ga_eitc_amount = federal_eitc * match_rate
+
+            return where(sb520_active, ga_eitc_amount, 0)
+
+    class ga_refundable_credits(Variable):
+        value_type = float
+        entity = TaxUnit
+        label = "Georgia refundable credits"
+        unit = USD
+        definition_period = YEAR
+        defined_for = StateCode.GA
+
+        def formula(tax_unit, period, parameters):
+            p_sb520 = parameters(period).gov.contrib.states.ga.sb520
+
+            sb520_active = p_sb520.in_effect
+
+            ga_ctc_amount = tax_unit("ga_ctc", period)
+            ga_eitc_amount = tax_unit("ga_eitc", period)
+
+            sb520_refundable = ga_ctc_amount + ga_eitc_amount
+
+            return where(sb520_active, sb520_refundable, 0)
+
+    class ga_non_refundable_credits(Variable):
+        value_type = float
+        entity = TaxUnit
+        label = "Georgia non-refundable credits"
+        unit = USD
+        definition_period = YEAR
+        defined_for = StateCode.GA
+
+        def formula(tax_unit, period, parameters):
+            p = parameters(period).gov.states.ga.tax.income.credits.non_refundable
+            p_sb520 = parameters(period).gov.contrib.states.ga.sb520
+
+            sb520_active = p_sb520.in_effect
+
+            baseline_credits = add(tax_unit, period, p)
+
+            ga_ctc_amount = tax_unit("ga_ctc", period)
+
+            return where(
+                sb520_active,
+                max_(baseline_credits - ga_ctc_amount, 0),
+                baseline_credits,
+            )
+
+    class ga_income_tax_before_non_refundable_credits(Variable):
+        value_type = float
+        entity = TaxUnit
+        label = "Georgia income tax before non-refundable credits"
+        unit = USD
+        definition_period = YEAR
+        defined_for = StateCode.GA
+        reference = (
+            "https://www.legis.ga.gov/api/legislation/document/20252026/242809#page=3",
+        )
+
+        def formula(tax_unit, period, parameters):
+            p = parameters(period).gov.states.ga.tax.income.main
+            p_sb520 = parameters(period).gov.contrib.states.ga.sb520
+
+            sb520_2027_active = p_sb520.brackets.in_effect
+
+            filing_status = tax_unit("filing_status", period)
+            status = filing_status.possible_values
+            income = tax_unit("ga_taxable_income", period)
+
+            sb520_tax = select(
+                [
+                    filing_status == status.SINGLE,
+                    filing_status == status.SEPARATE,
+                    filing_status == status.JOINT,
+                    filing_status == status.HEAD_OF_HOUSEHOLD,
+                    filing_status == status.SURVIVING_SPOUSE,
+                ],
+                [
+                    p_sb520.brackets.single.calc(income),
+                    p_sb520.brackets.separate.calc(income),
+                    p_sb520.brackets.joint.calc(income),
+                    p_sb520.brackets.head_of_household.calc(income),
+                    p_sb520.brackets.surviving_spouse.calc(income),
+                ],
+            )
+
+            baseline_tax = select(
+                [
+                    filing_status == status.SINGLE,
+                    filing_status == status.SEPARATE,
+                    filing_status == status.JOINT,
+                    filing_status == status.HEAD_OF_HOUSEHOLD,
+                    filing_status == status.SURVIVING_SPOUSE,
+                ],
+                [
+                    p.single.calc(income),
+                    p.separate.calc(income),
+                    p.joint.calc(income),
+                    p.head_of_household.calc(income),
+                    p.surviving_spouse.calc(income),
+                ],
+            )
+
+            return where(sb520_2027_active, sb520_tax, baseline_tax)
+
+    class reform(Reform):
+        def apply(self):
+            self.update_variable(ga_standard_deduction)
+            self.update_variable(ga_deductions)
+            self.update_variable(ga_ctc)
+            self.update_variable(ga_eitc)
+            self.update_variable(ga_refundable_credits)
+            self.update_variable(ga_non_refundable_credits)
+            self.update_variable(ga_income_tax_before_non_refundable_credits)
+
+    return reform
+
+
+def create_ga_sb520_reform(parameters, period, bypass: bool = False):
+    if bypass:
+        return create_ga_sb520()
+
+    p_sb520 = parameters.gov.contrib.states.ga.sb520
+
+    reform_active = False
+    current_period = period_(period)
+
+    for i in range(5):
+        p_at_period = p_sb520(current_period)
+        if p_at_period.in_effect or p_at_period.brackets.in_effect:
+            reform_active = True
+            break
+        current_period = current_period.offset(1, "year")
+
+    if reform_active:
+        return create_ga_sb520()
+    else:
+        return None
+
+
+ga_sb520 = create_ga_sb520_reform(None, None, bypass=True)
diff --git a/policyengine_us/tests/policy/contrib/states/ga/sb520/integration.yaml b/policyengine_us/tests/policy/contrib/states/ga/sb520/integration.yaml
new file mode 100644
index 00000000000..82fa5923f85
--- /dev/null
+++ b/policyengine_us/tests/policy/contrib/states/ga/sb520/integration.yaml
@@ -0,0 +1,216 @@
+- name: Case 1, single filer with 2026 provisions.
+  period: 2026
+  absolute_error_margin: 0.1
+  reforms: policyengine_us.reforms.states.ga.sb520.ga_sb520
+  input:
+    gov.contrib.states.ga.sb520.in_effect: true
+    people:
+      person1:
+        age: 30
+        employment_income: 50_000
+    tax_units:
+      tax_unit:
+        members: [person1]
+    households:
+      household:
+        members: [person1]
+        state_code: GA
+  output:
+    ga_standard_deduction: 17_000
+
+- name: Case 2, joint filers with 2026 provisions and children.
+  period: 2026
+  absolute_error_margin: 0.1
+  reforms: policyengine_us.reforms.states.ga.sb520.ga_sb520
+  input:
+    gov.contrib.states.ga.sb520.in_effect: true
+    people:
+      person1:
+        age: 35
+        employment_income: 80_000
+      person2:
+        age: 33
+      child1:
+        age: 5
+      child2:
+        age: 8
+    tax_units:
+      tax_unit:
+        members: [person1, person2, child1, child2]
+    households:
+      household:
+        members: [person1, person2, child1, child2]
+        state_code: GA
+  output:
+    ga_standard_deduction: 34_000
+    # Only child1 (age 5) qualifies - GA CTC age threshold is under 6
+    ga_ctc: 1_250
+
+- name: Case 3, standard deduction phase-out.
+  period: 2026
+  absolute_error_margin: 0.1
+  reforms: policyengine_us.reforms.states.ga.sb520.ga_sb520
+  input:
+    gov.contrib.states.ga.sb520.in_effect: true
+    people:
+      person1:
+        age: 45
+        employment_income: 320_000
+      person2:
+        age: 43
+    tax_units:
+      tax_unit:
+        members: [person1, person2]
+    households:
+      household:
+        members: [person1, person2]
+        state_code: GA
+  output:
+    # AGI: 320,000
+    # Excess: 320,000 - 280,000 = 40,000
+    # Phase-out: 40,000 * 0.25 = 10,000
+    # Deduction: 34,000 - 10,000 = 24,000
+    ga_standard_deduction: 24_000
+
+- name: Case 4, Georgia EITC with federal EITC.
+  period: 2026
+  absolute_error_margin: 1
+  reforms: policyengine_us.reforms.states.ga.sb520.ga_sb520
+  input:
+    gov.contrib.states.ga.sb520.in_effect: true
+    people:
+      person1:
+        age: 30
+        employment_income: 25_000
+      child1:
+        age: 5
+    tax_units:
+      tax_unit:
+        members: [person1, child1]
+    households:
+      household:
+        members: [person1, child1]
+        state_code: GA
+  output:
+    # GA EITC = 20% of federal EITC
+    # Federal EITC for single parent with 1 child earning $25,000 is approximately $4,242
+    # GA EITC = $4,242 * 0.20 = $848
+    ga_eitc: 848
+
+- name: Case 5, 2027 progressive brackets for single filer.
+  period: 2027
+  absolute_error_margin: 1
+  reforms: policyengine_us.reforms.states.ga.sb520.ga_sb520
+  input:
+    gov.contrib.states.ga.sb520.in_effect: true
+    gov.contrib.states.ga.sb520.brackets.in_effect: true
+    people:
+      person1:
+        age: 30
+        employment_income: 50_000
+    tax_units:
+      tax_unit:
+        members: [person1]
+    households:
+      household:
+        members: [person1]
+        state_code: GA
+  output:
+    # With SB520 deduction of 17,000:
+    # Taxable income: 50,000 - 17,000 = 33,000
+    # Tax: 15,000 * 0.02 + 15,000 * 0.04 + 3,000 * 0.06
+    # = 300 + 600 + 180 = 1,080
+    ga_income_tax_before_non_refundable_credits: 1_080
+
+- name: Case 6, standard deduction fully phased out.
+  period: 2026
+  absolute_error_margin: 0.1
+  reforms: policyengine_us.reforms.states.ga.sb520.ga_sb520
+  input:
+    gov.contrib.states.ga.sb520.in_effect: true
+    people:
+      person1:
+        age: 40
+        employment_income: 500_000
+    tax_units:
+      tax_unit:
+        members: [person1]
+    households:
+      household:
+        members: [person1]
+        state_code: GA
+  output:
+    # AGI: 500,000
+    # Threshold for single: 140,000
+    # Excess: 500,000 - 140,000 = 360,000
+    # Phase-out: 360,000 * 0.25 = 90,000
+    # Deduction: max(17,000 - 90,000, 0) = 0
+    ga_standard_deduction: 0
+
+- name: Case 7, CTC with no qualifying children (all above age 6).
+  period: 2026
+  absolute_error_margin: 0.1
+  reforms: policyengine_us.reforms.states.ga.sb520.ga_sb520
+  input:
+    gov.contrib.states.ga.sb520.in_effect: true
+    people:
+      person1:
+        age: 40
+        employment_income: 60_000
+      child1:
+        age: 10
+      child2:
+        age: 14
+    tax_units:
+      tax_unit:
+        members: [person1, child1, child2]
+    households:
+      household:
+        members: [person1, child1, child2]
+        state_code: GA
+  output:
+    # No children under age 6, so no GA CTC
+    ga_ctc: 0
+
+- name: Case 8, high income single filer with no EITC.
+  period: 2026
+  absolute_error_margin: 0.1
+  reforms: policyengine_us.reforms.states.ga.sb520.ga_sb520
+  input:
+    gov.contrib.states.ga.sb520.in_effect: true
+    people:
+      person1:
+        age: 35
+        employment_income: 100_000
+    tax_units:
+      tax_unit:
+        members: [person1]
+    households:
+      household:
+        members: [person1]
+        state_code: GA
+  output:
+    # Income too high for federal EITC, so no GA EITC
+    ga_eitc: 0
+
+- name: Case 9, income exactly at phase-out threshold.
+  period: 2026
+  absolute_error_margin: 0.1
+  reforms: policyengine_us.reforms.states.ga.sb520.ga_sb520
+  input:
+    gov.contrib.states.ga.sb520.in_effect: true
+    people:
+      person1:
+        age: 40
+        employment_income: 140_000
+    tax_units:
+      tax_unit:
+        members: [person1]
+    households:
+      household:
+        members: [person1]
+        state_code: GA
+  output:
+    # AGI exactly at threshold (140,000 for single)
+    # No phase-out yet
+    ga_standard_deduction: 17_000