Model Medicaid CE recent incarceration exception

[daphnehanse11]

Summary

Fixes #8268 by modeling the Medicaid community engagement incarceration exclusion/exception.

Regulatory Authority

• Public Law 119-21, Section 71119, mandatory exceptions: https://www.congress.gov/119/plaws/publ21/PLAW-119publ21.pdf#page=238
• Public Law 119-21, Section 71119, specified excluded individuals: https://www.congress.gov/119/plaws/publ21/PLAW-119publ21.pdf#page=242
• CMS CMCS Informational Bulletin, December 8, 2025: https://www.medicaid.gov/federal-policy-guidance/downloads/cib12082025.pdf#page=6

Modeled Scope

Requirement	Implementation	Tests
Current inmate exclusion	medicaid_work_requirement_eligible reads existing is_incarcerated	Case 10
Three-month recent-incarceration exception	New was_recently_incarcerated_for_medicaid_ce input and CE rollup condition	Case 11
No incarceration fallback	No current/recent incarceration leaves nonworking adult ineligible	Case 12

Not Modeled

• Date-based application-month lookback logic.
• Operational verification or documentation workflows.

Validation

• uv run policyengine-core test policyengine_us/tests/policy/baseline/gov/hhs/medicaid/eligibility/medicaid_work_requirement_eligible.yaml -c policyengine_us -v
• uv run policyengine-core test policyengine_us/tests/policy/baseline/gov/hhs/medicaid/eligibility -c policyengine_us
• uv run --extra dev ruff format .
• uv run --extra dev ruff check .

Files Added

• policyengine_us/variables/gov/hhs/medicaid/eligibility/was_recently_incarcerated_for_medicaid_ce.py
• changelog.d/8268.fixed.md
• sources/working_references.md

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (8f458cd) to head (c15c0a3).
⚠️ Report is 28 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##              main     #8371   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files            4         2    -2     
  Lines           52        41   -11     
=========================================
- Hits            52        41   -11     

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

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