add parameters

policyengine_us/parameters/gov/states/va/tax/income/deductions/itemized/reduction/applicable.yaml

@@ -0,0 +1,31 @@
+description: Virginia sums up the following deductions to compute the itemized deductions reduction amount. 
+values:
+  2013-01-01:
+    - medical_expense_deduction
+    - salt_deduction
+    - interest_deduction
+    - charitable_deduction
+    - casualty_loss_deduction
+metadata:
+  unit: list
+  period: year
+  label: Virginia itemized deductions reduction applicable deduction sources
+  reference:
+    - title: 2020 Virginia Schedule A Itemized Deductions
+      href: https://www.tax.virginia.gov/sites/default/files/taxforms/individual-income-tax/2020/schedule-and-instructions-2020.pdf#page=1
+    - title: 2021 Virginia Schedule A Itemized Deductions
+      href: https://www.tax.virginia.gov/sites/default/files/taxforms/individual-income-tax/2021/schedule-2021.pdf#page=2
+    - title: 2022 Virginia Schedule A Itemized Deductions
+      href: https://www.tax.virginia.gov/sites/default/files/taxforms/individual-income-tax/2022/schedule-2022.pdf#page=2
+    - title: 2019 Instructions for Virginia Schedule A Itemized Deductions
+      href: https://www.tax.virginia.gov/sites/default/files/vatax-pdf/2019-schedule-a-instructions.pdf#page=2
+    - title: 2013 Instruction 1040 Schedule A
+      href: https://www.irs.gov/pub/irs-prior/i1040sca--2013.pdf#page=14
+    - title: 2014 Instruction 1040 Schedule A
+      href: https://www.irs.gov/pub/irs-prior/i1040sca--2014.pdf#page=13
+    - title: 2015 Instruction 1040 Schedule A
+      href: https://www.irs.gov/pub/irs-prior/i1040sca--2015.pdf#page=13
+    - title: 2016 Instructions for Schedule A (Form 1040)
+      href: https://www.irs.gov/pub/irs-prior/i1040sca--2016.pdf#page=13
+    - title: 2017 Instructions for Schedule A (Form 1040)
+      href: https://www.irs.gov/pub/irs-prior/i1040sca--2017.pdf#page=14

policyengine_us/parameters/gov/states/va/tax/income/deductions/itemized/reduction/reducible.yaml

@@ -0,0 +1,30 @@
+description: Virginia reduced the applicable itemized deductions by the following deductions to compute the itemized deductions reduction amount.
+values:
+  2013-01-01:
+    - medical_expense_deduction
+    - investment_interest_expense
+    - gambling_losses
+    - casualty_loss_deduction
+metadata:
+  unit: list
+  period: year
+  label: Virginia itemized deductions reduction reducible deduction sources
+  reference:
+    - title: 2020 Virginia Schedule A Itemized Deductions
+      href: https://www.tax.virginia.gov/sites/default/files/taxforms/individual-income-tax/2020/schedule-and-instructions-2020.pdf#page=1
+    - title: 2021 Virginia Schedule A Itemized Deductions
+      href: https://www.tax.virginia.gov/sites/default/files/taxforms/individual-income-tax/2021/schedule-2021.pdf#page=2
+    - title: 2022 Virginia Schedule A Itemized Deductions
+      href: https://www.tax.virginia.gov/sites/default/files/taxforms/individual-income-tax/2022/schedule-2022.pdf#page=2
+    - title: 2019 Instructions for Virginia Schedule A Itemized Deductions
+      href: https://www.tax.virginia.gov/sites/default/files/vatax-pdf/2019-schedule-a-instructions.pdf#page=2
+    - title: 2013 Instruction 1040 Schedule A
+      href: https://www.irs.gov/pub/irs-prior/i1040sca--2013.pdf#page=14
+    - title: 2014 Instruction 1040 Schedule A
+      href: https://www.irs.gov/pub/irs-prior/i1040sca--2014.pdf#page=13
+    - title: 2015 Instruction 1040 Schedule A
+      href: https://www.irs.gov/pub/irs-prior/i1040sca--2015.pdf#page=13
+    - title: 2016 Instructions for Schedule A (Form 1040)
+      href: https://www.irs.gov/pub/irs-prior/i1040sca--2016.pdf#page=13
+    - title: 2017 Instructions for Schedule A (Form 1040)
+      href: https://www.irs.gov/pub/irs-prior/i1040sca--2017.pdf#page=14

policyengine_us/variables/gov/states/va/tax/income/deductions/va_reduced_itemized_deductions.py

@@ -11,13 +11,6 @@ class va_reduced_itemized_deductions(Variable):
     defined_for = StateCode.VA
 
     def formula(tax_unit, period, parameters):
-        # The federal limitation on itemized deductions does not apply during the TCJA period
-        # Virginia still applies the limitation
-        year = period.start.year
-        if year >= 2018 and year <= 2026:
-            instant_str = f"2017-01-01"
-        else:
-            instant_str = period
         p_va = parameters(period).gov.states.va.tax.income.deductions.itemized
 
         uncapped_state_and_local_tax = tax_unit(
@@ -31,29 +24,25 @@ def formula(tax_unit, period, parameters):
         applicable_ded = add(
             tax_unit,
             period,
-            [
-                "medical_expense_deduction",
-                "salt_deduction",
-                "interest_deduction",
-                "charitable_deduction",
-                "casualty_loss_deduction",
-            ],
+            p_va.reduction.applicable,
         )
         # Line 2 medical expense ded., interest ded., casualty loss ded., and gambling losses
         reducible_ded = add(
             tax_unit,
             period,
-            [
-                "medical_expense_deduction",
-                "investment_interest_expense",
-                "casualty_loss_deduction",
-                "gambling_losses",
-            ],
+            p_va.reduction.reducible,
         )
         # Line 3 - subtract Line 2 from line 1
         excess_ded = max_(applicable_ded - reducible_ded, 0)
         # If 0 - no reduction
         # Line 4 - IRS deduction rate of excess
+        # The federal limitation on itemized deductions does not apply during the TCJA period
+        # Virginia still applies the limitation
+        year = period.start.year
+        if year >= 2018 and year <= 2026:
+            instant_str = f"2017-01-01"
+        else:
+            instant_str = period
         p_irs = parameters(instant_str).gov.irs.deductions.itemized.limitation
         excess_ded_fraction = excess_ded * p_irs.itemized_deduction_rate
         # Line 5 Federal AGI