Count a filer's gains without netted losses and Social Security once in Montana's elderly credit income

changelog.d/fix-mt-ehrc-filer-gains-ss-roles.fixed.md

@@ -0,0 +1 @@
+Montana's elderly homeowner/renter credit now counts each person's capital gains without losses netted on the same return or carried over from a prior year, and counts Social Security once when a person is input as both a tax unit dependent and the head or spouse.

policyengine_us/parameters/gov/states/mt/tax/income/credits/elderly_homeowner_or_renter/gross_income_sources.yaml

@@ -80,8 +80,11 @@ values:
     - mt_elderly_homeowner_or_renter_credit_received
     - mt_elderly_homeowner_or_renter_credit_federal_refundable_credits
     - mt_elderly_homeowner_or_renter_credit_property_tax_rebate_received
-# Social Security under § 15-30-2337(9)(a)(viii) is added separately in
-# mt_elderly_homeowner_or_renter_credit_gross_household_income.py because the
-# untaxed portion is computed as social_security - taxable_social_security.
+# mt_elderly_homeowner_or_renter_credit_gross_household_income.py adds three
+# items separately: a tax unit dependent's own gross income (their income is
+# on their own return, not in adjusted_gross_income_person); the untaxed
+# portion of Social Security under § 15-30-2337(9)(a)(viii), computed as
+# social_security less the taxable part already counted; and the losses
+# deducted in federal AGI.
 # This year's elderly homeowner/renter credit is excluded to avoid a circular
 # reference; the credit received during the year counts instead.

policyengine_us/tests/policy/baseline/gov/states/mt/tax/income/credits/elderly_homeowner_or_renter/mt_elderly_homeowner_or_renter_credit.yaml

@@ -842,3 +842,159 @@
     mt_elderly_homeowner_or_renter_credit_pre_one_claimant: [50, 410]
     mt_elderly_homeowner_or_renter_credit_selected_claimant: [false, true]
     mt_elderly_homeowner_or_renter_credit: [0, 410]
+
+- name: 2024 Schedule 2EC, a household member's netted capital loss does not raise the credit
+  period: 2024
+  absolute_error_margin: 0.01
+  input:
+    people:
+      person1:
+        age: 70
+        taxable_pension_income: 20_000
+        real_estate_taxes: 2_000
+      person2:
+        age: 30
+        long_term_capital_gains: 10_000
+        short_term_capital_gains: -4_000
+    tax_units:
+      tax_unit1:
+        members: [person1]
+      tax_unit2:
+        members: [person2]
+    households:
+      household:
+        members: [person1, person2]
+        state_name: MT
+  output:
+    # Line 5 = 20_000; line 17 = 10_000 (the gain without the loss); line
+    # 18 = 30_000; line 20 = 17_400; line 22 = 17_400 x 0.05 = 870; line 27 =
+    # 2_000 - 870 = 1_130; line 29 = 100%; line 30 = 1_130. Netting the loss
+    # would give line 18 = 26_000, line 22 = 670 and the 1_150 cap.
+    mt_elderly_homeowner_or_renter_credit_net_household_income: [870, 0]
+    mt_elderly_homeowner_or_renter_credit: [1_130, 0]
+
+- name: 2024 Schedule 2EC, a capital loss netted between spouses on a joint return is added back once
+  period: 2024
+  absolute_error_margin: 0.01
+  input:
+    people:
+      person1:
+        age: 70
+        taxable_pension_income: 20_000
+        long_term_capital_gains: 10_000
+        real_estate_taxes: 2_000
+      person2:
+        age: 68
+        short_term_capital_gains: -4_000
+    tax_units:
+      tax_unit:
+        members: [person1, person2]
+    households:
+      household:
+        members: [person1, person2]
+        state_name: MT
+  output:
+    # Federal AGI 20_000 + 10_000 - 4_000 = 26_000; the 4_000 loss is added
+    # back once. Line 18 = 30_000; line 22 = 870; line 30 = 1_130.
+    mt_elderly_homeowner_or_renter_credit_net_household_income: [870, 0]
+    mt_elderly_homeowner_or_renter_credit: [1_130, 0]
+
+- name: 2024 Schedule 2EC, a minor filing alone in the household counts once
+  period: 2024
+  absolute_error_margin: 0.01
+  input:
+    people:
+      person1:
+        age: 70
+        taxable_pension_income: 20_000
+        real_estate_taxes: 2_000
+        is_tax_unit_dependent: false
+      person2:
+        age: 16
+        employment_income: 10_000
+        is_tax_unit_dependent: false
+    tax_units:
+      tax_unit1:
+        members: [person1]
+      tax_unit2:
+        members: [person2]
+    households:
+      household:
+        members: [person1, person2]
+        state_name: MT
+  output:
+    # Line 18 = 20_000 + 10_000 = 30_000; line 30 = 1_130. Counting the
+    # minor's wages twice would give 40_000, line 22 = 1_370 and a credit of
+    # (2_000 - 1_370) x 30% = 189.
+    mt_elderly_homeowner_or_renter_credit: [1_130, 0]
+
+- name: 2024 Schedule 2EC, a capital loss carryover does not raise the credit
+  period: 2024
+  absolute_error_margin: 0.01
+  input:
+    people:
+      person1:
+        age: 70
+        taxable_pension_income: 20_000
+        long_term_capital_gains: 6_000
+        long_term_capital_loss_carryover: 4_000
+        real_estate_taxes: 2_000
+    tax_units:
+      tax_unit:
+        members: [person1]
+    households:
+      household:
+        members: [person1]
+        state_name: MT
+  output:
+    # Line 5 = 20_000; line 7 = the year's 10_000 gain; line 18 = 30_000;
+    # line 22 = 870; line 30 = 1_130. Counting the 6_000 net would give line
+    # 18 = 26_000, line 22 = 670 and the 1_150 cap.
+    mt_elderly_homeowner_or_renter_credit: 1_130
+
+- name: 2024 Schedule 2EC, a carryover against a net loss supplied directly adds no gain
+  period: 2024
+  absolute_error_margin: 0.01
+  input:
+    people:
+      person1:
+        age: 70
+        taxable_pension_income: 30_000
+        capital_gains: -5_000
+        long_term_capital_loss_carryover: 5_000
+        real_estate_taxes: 2_000
+    tax_units:
+      tax_unit:
+        members: [person1]
+    households:
+      household:
+        members: [person1]
+        state_name: MT
+  output:
+    # Line 18 = 30_000; line 22 = 17_400 x 0.05 = 870; line 30 = 1_130.
+    # Counting the carryover as a gain would give 35_000 and 880 x 40% = 352.
+    mt_elderly_homeowner_or_renter_credit: 1_130
+
+- name: 2024 Schedule 2EC, a dependent's gain counts when another person's capital_gains is supplied
+  period: 2024
+  absolute_error_margin: 0.01
+  input:
+    people:
+      person1:
+        age: 70
+        taxable_pension_income: 20_000
+        capital_gains: 0
+        real_estate_taxes: 2_000
+      person2:
+        age: 16
+        long_term_capital_gains: 10_000
+    tax_units:
+      tax_unit:
+        members: [person1, person2]
+    households:
+      household:
+        members: [person1, person2]
+        state_name: MT
+  output:
+    # Line 18 = 20_000 + 10_000 = 30_000; line 22 = 870; line 30 = 1_130.
+    mt_elderly_homeowner_or_renter_credit: [1_130, 0]