Apply New Mexico's rules for a filer who can be claimed as a dependent

changelog.d/claimable-filer-nm.fixed.md

@@ -0,0 +1 @@
+Apply New Mexico's rules for a filer who can be claimed as a dependent: no child income tax credit when every filer can be claimed (NMSA 7-2-18.34), no childless EITC, child care credit child or certain-dependents deduction on a return with a claimable filer, and the medical care credit, property tax rebate and centenarian exemption only for a filer who meets the age test and cannot be claimed; the medical expense credit and exemption and the childless EITC now test filers' ages, not a dependent's, and the EITC's child route also counts older qualifying children under IRC 32(c)(3) (a dependent aged 18, a student under 24 or a permanently disabled child).

policyengine_us/tests/core/test_claimable_filer_nm_invariants.py

@@ -0,0 +1,95 @@
+"""New Mexico rules for a filer who can be claimed as a dependent.
+
+Several credits and exemptions bar "a dependent of another individual", and
+dependent-based amounts need dependents that a return with a claimable filer
+cannot have (IRC 152(b)(1)).
+
+For couples with either, both or neither spouse claimed:
+
+1. Swap invariance: each output is the same under either head/spouse
+   labelling (Hypothesis batches, the seeded population and the crafted
+   centenarian cases).
+2. Monotonicity: marking another filer as claimed never raises an output
+   (seeded population and crafted cases only).
+
+The crafted cases add spouses aged 100 or older, whom the generated population
+(ages 18 to 90) never has.
+"""
+
+import pytest
+from hypothesis import HealthCheck, given, settings
+from hypothesis import strategies as st
+
+from policyengine_us.tests.core.test_claimable_filer_federal_invariants import (
+    check_monotone,
+    check_swap,
+)
+from policyengine_us.tests.core.test_dependent_elsewhere_head_spouse_swap_invariance import (
+    CLAIM_PATTERNS,
+    _crafted_cases,
+    _seeded_couples,
+    adults,
+    dependents,
+)
+
+STATES = ["NM"]
+YEARS = [2023, 2025, 2026]
+OUTPUTS = [
+    "nm_ctc",
+    "nm_medical_expense_credit",
+    "nm_medical_expense_exemption",
+    "nm_eitc",
+    "nm_deduction_for_certain_dependents",
+    "nm_property_tax_rebate",
+    "nm_cdcc_max_amount",
+    "nm_hundred_year_exemption",
+]
+
+
+def _centenarian_cases():
+    # One or both spouses aged 100 or older, with income to exempt.
+    centenarian = {"age": 101, "taxable_pension_income": 20_000.0}
+    older = {"age": 103, "taxable_interest_income": 5_000.0}
+    younger = {"age": 70, "social_security_retirement": 12_000.0}
+    return [
+        {
+            "state": "NM",
+            "adults": couple,
+            "dependents": [],
+            "claimed": claimed,
+        }
+        for couple in ([centenarian, younger], [centenarian, older])
+        for claimed in [(True, False), (False, True), (True, True)]
+    ]
+
+
+@st.composite
+def couples(draw):
+    return {
+        "state": draw(st.sampled_from(STATES)),
+        "adults": [draw(adults()), draw(adults())],
+        "dependents": draw(st.lists(dependents(), max_size=2)),
+        "claimed": draw(st.sampled_from(CLAIM_PATTERNS)),
+    }
+
+
+@settings(
+    max_examples=2,
+    deadline=None,
+    derandomize=True,
+    suppress_health_check=[HealthCheck.too_slow, HealthCheck.data_too_large],
+)
+@given(st.sampled_from(YEARS), st.lists(couples(), min_size=6, max_size=12))
+def test_nm_claimable_filer_rules_are_label_free(year, units):
+    check_swap(units, year, OUTPUTS)
+
+
+@pytest.mark.parametrize("year", YEARS)
+def test_nm_claimable_filer_rules_seeded_population(year):
+    units = (
+        _seeded_couples(STATES, per_state=3)
+        + _crafted_cases(STATES)
+        + _centenarian_cases()
+    )
+    check_swap(units, year, OUTPUTS)
+    check_monotone(units, year, OUTPUTS)

policyengine_us/tests/policy/baseline/gov/states/nm/tax/income/credits/cdcc/nm_cdcc_eligible_child.yaml

@@ -24,3 +24,140 @@
     is_tax_unit_dependent: true
   output:
     nm_cdcc_eligible_child: true
+
+- name: 2025 joint return with one claimable spouse has no eligible child (the claimable spouse is the head)
+  period: 2025
+  input:
+    people:
+      person_a:
+        age: 30
+        claimed_as_dependent_on_another_return: true
+        is_tax_unit_head: true
+        is_tax_unit_spouse: false
+      person_b:
+        age: 30
+        is_tax_unit_head: false
+        is_tax_unit_spouse: true
+      child:
+        age: 5
+    tax_units:
+      tax_unit:
+        members: [person_a, person_b, child]
+        filing_status: JOINT
+    households:
+      household:
+        members: [person_a, person_b, child]
+        state_code: NM
+  output:
+    # NMSA 7-2-18.1 counts IRC 152 dependents; IRC 152(b)(1) leaves such a
+    # return none.
+    nm_cdcc_eligible_child: [false, false, false]
+
+- name: 2025 joint return with one claimable spouse has no eligible child (the claimable spouse is the spouse)
+  period: 2025
+  input:
+    people:
+      person_b:
+        age: 30
+        is_tax_unit_head: true
+        is_tax_unit_spouse: false
+      person_a:
+        age: 30
+        claimed_as_dependent_on_another_return: true
+        is_tax_unit_head: false
+        is_tax_unit_spouse: true
+      child:
+        age: 5
+    tax_units:
+      tax_unit:
+        members: [person_b, person_a, child]
+        filing_status: JOINT
+    households:
+      household:
+        members: [person_b, person_a, child]
+        state_code: NM
+  output:
+    # NMSA 7-2-18.1 counts IRC 152 dependents; IRC 152(b)(1) leaves such a
+    # return none.
+    nm_cdcc_eligible_child: [false, false, false]
+
+- name: 2025 joint return with neither spouse claimable has an eligible child
+  period: 2025
+  input:
+    people:
+      person_a:
+        age: 30
+      person_b:
+        age: 30
+      child:
+        age: 5
+    tax_units:
+      tax_unit:
+        members: [person_a, person_b, child]
+        filing_status: JOINT
+    households:
+      household:
+        members: [person_a, person_b, child]
+        state_code: NM
+  output:
+    nm_cdcc_eligible_child: [false, false, true]
+
+# Publication 501, Dependent Taxpayer Test: a filer whose would-be claimant is not
+# required to file and files no return or only for a refund can claim dependents.
+- name: 2025 joint return whose claimable spouse is within the filing exception has an eligible child (the claimable spouse is the head)
+  period: 2025
+  input:
+    people:
+      person_a:
+        age: 30
+        claimable_as_dependent_on_another_return: true
+        dependent_claimant_filing_exception: true
+        is_tax_unit_head: true
+        is_tax_unit_spouse: false
+      person_b:
+        age: 30
+        is_tax_unit_head: false
+        is_tax_unit_spouse: true
+      child:
+        age: 5
+        is_tax_unit_head: false
+        is_tax_unit_spouse: false
+    tax_units:
+      tax_unit:
+        members: [person_a, person_b, child]
+        filing_status: JOINT
+    households:
+      household:
+        members: [person_a, person_b, child]
+        state_code: NM
+  output:
+    nm_cdcc_eligible_child: [false, false, true]
+
+- name: 2025 joint return whose claimable spouse is within the filing exception has an eligible child (the claimable spouse is the spouse)
+  period: 2025
+  input:
+    people:
+      person_b:
+        age: 30
+        is_tax_unit_head: true
+        is_tax_unit_spouse: false
+      person_a:
+        age: 30
+        claimable_as_dependent_on_another_return: true
+        dependent_claimant_filing_exception: true
+        is_tax_unit_head: false
+        is_tax_unit_spouse: true
+      child:
+        age: 5
+        is_tax_unit_head: false
+        is_tax_unit_spouse: false
+    tax_units:
+      tax_unit:
+        members: [person_b, person_a, child]
+        filing_status: JOINT
+    households:
+      household:
+        members: [person_b, person_a, child]
+        state_code: NM
+  output:
+    nm_cdcc_eligible_child: [false, false, true]