Update SNAP ABAWD work requirements for HR1 (P.L. 119-21) with missing exemptions and CA delay

[MaxGhenis]

Replaces #7415 (rebased to resolve merge conflicts). Original PR by @hua7450.

Summary

Updates SNAP ABAWD work requirements to reflect P.L. 119-21 (One Big Beautiful Bill Act), adds missing non-age work registration exemptions per 7 U.S.C. 2015(o)(3)(D), and properly handles California's delayed HR1 adoption (ACL 25-93) via a centralized state routing variable.

Closes #7446 is tracked as a follow-up (HI/AK delayed adoption parameters).

Regulatory Authority

• P.L. 119-21, Section 10102(a) — ABAWD modifications
• 7 U.S.C. 2015(o)(3) — ABAWD exemptions
• 7 CFR 273.24 — ABAWD time limits
• 7 CFR 273.7(b)(1) — Work registration exemptions
• California ACL 25-93 — CA delays HR1 to June 1, 2026
• FNS ABAWD Exceptions Implementation Memo — HR1 exception changes
• FNS ABAWD Waivers Implementation Memo — HI/AK waiver authority
• PRWORA (P.L. 104-193), Section 824 — Original ABAWD provisions (1997-03-01)
• FRA 2023 (P.L. 118-5), Section 311 — Age phase-in (50→51→53→55)

Changes

Federal parameter updates

• Corrected effective dates to 2025-07-04 (P.L. 119-21 enactment date)
• Backdated ABAWD age exemption to 1997-03-01 (PRWORA effective date) with full FRA 2023 phase-in history:
  • 1997-03-01: 50 (original, ages 18-49 subject)
  • 2023-09-01: 51 (FRA phase 1, "over 51")
  • 2023-10-01: 53 (FRA phase 2, "over 53")
  • 2024-10-01: 55 (FRA phase 3, "over 55")
  • 2025-07-04: 65 (HR1/OBBB, "over 65")
• Dependent age threshold backdated to 1997-03-01 (unchanged value of 18 until HR1 → 14)

HI/AK exemption removed

• Removed blanket state exemption logic (is_exempt_state) from meets_snap_abawd_work_requirements formula
• Both HI and AK are implementing ABAWD (effective Nov 1, 2025):
  • Hawaii DHS FAQ confirms implementation
  • Alaska DHS OBBBA Impacts confirms implementation
• exempt_states.yaml parameter retained with updated description documenting preferential waiver authority per 7 U.S.C. 2015(o)(4)(A)(ii) and 2015(o)(7)
• HI/AK delayed adoption parameters (effective 2025-11-01) tracked in Add HI/AK delayed ABAWD adoption parameters (Nov 2025) #7446

New variable: is_snap_abawd_hr1_in_effect

Centralizes state-level HR1 adoption routing using select(). States that delay HR1 adoption (currently CA) have their own hr1_in_effect parameter; all other states use the federal in_effect parameter.

New variable: is_snap_work_registration_exempt_non_age

Implements 7 CFR 273.7(b)(1) non-age exemptions used by ABAWD exemption (D):

• (ii) Physically/mentally unfit (is_disabled)
• (iv) Caring for dependent child under 6 or incapacitated person
• (v) Receiving unemployment compensation
• (viii) Enrolled at least half-time in school/training/higher ed

Intentionally omitted (documented in code):

• (iii) Subject to TANF work requirements — requires TANF enrollment input
• (vi) Drug/alcohol treatment participant — requires treatment program input
• (vii) Working 30+ hrs/week — handled separately in ABAWD work activity check

Not implemented (documented in code)

• (F)-(G) Native American/Indian exemptions per IHCIA definitions — requires tribal membership input variable

Refactored meets_snap_abawd_work_requirements

• Uses is_snap_abawd_hr1_in_effect for pre/post HR1 branching
• Structure follows 7 U.S.C. 2015(o)(3) letter by letter: (A) age, (B) disability, (C) parent, (D) work reg exempt, (E) pregnant
• Pre-HR1 snapshot uses parameters("2025-06-01") (last month before effective date)

Deleted

• ca_meets_snap_abawd_work_requirements.py and its tests (functionality merged into federal variable via is_snap_abawd_hr1_in_effect routing)

Behavioral Impact

• Adding three ABAWD exemptions (child under 6, student, UI recipient) is a correct behavioral change — these exist in law but were missing
• Removing HI/AK blanket exemption is a correct behavioral change — both states are implementing ABAWD
• Backdating age parameters and adding FRA phase-in is a correct behavioral change for historical simulations

Test plan

• 56 tests pass (policyengine-core test .../work_requirements -c policyengine_us -v)
• Broader SNAP tests pass
• Microsimulation test passes

Tests organized by statutory provision:

• Pre-HR1 (7 CFR 273.24(c)): age boundaries (17/18, 54/55), disabled, work hours (19/20), parent with child under 18, pregnant, incapacitated caregiver, homeless, veteran
• Post-HR1 (7 U.S.C. 2015(o)(3)): age boundaries (64/65), ages 55-64 no longer exempt, disabled, parent with child under 14 (boundary at 15), new work-reg-exempt paths (student, UI, child under 6), removed exemptions (homeless/veteran)
• CA delayed adoption (ACL 25-93): age 55 still exempt, homeless/veteran still exempt, parent with child under 18, non-exempt fails
• HR1 routing (is_snap_abawd_hr1_in_effect): TX post/pre-HR1, CA pre/post-adoption

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (2dd3b64) to head (ca57403).
⚠️ Report is 31 commits behind head on main.

Additional details and impacted files

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  Coverage   100.00%   100.00%           
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  Files            2         4    +2     
  Lines           24        79   +55     
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+ Hits            24        79   +55     

Flag	Coverage Δ
unittests	100.00% <100.00%> (ø)

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