Add Arizona Child Care Assistance Program

[hua7450]

Summary

Fixes #8370.

Adds Arizona's Child Care Assistance Program (CCAP), including:

• Eligibility for Arizona families with an eligible child under age 13 who is a citizen or qualified noncitizen (CCDF, 45 CFR 98.20).
• Initial and ongoing income eligibility using the DES FFY 2026 fee schedule.
• az_ccap_enrolled to apply ongoing/redetermination eligibility through 85% SMI.
• DES daily copays by fee level, with formula-based copay exemptions for employed Cash Assistance families, protective services, and foster care pathways.
• A without-regard-to-income (categorical) eligibility pathway for the same families (R6-5-4914(A)).
• DES reimbursement rates by provider type, child age group, quality status, formula-derived special-needs child status, and school-age season.
• Monthly subsidy calculation as max(0, min(pre-subsidy childcare expenses, state maximum reimbursement) - copay).

Regulatory Authority

• Arizona DES child care assistance eligibility page.
• DES CCA-0229A, Child Care Assistance Gross Monthly Income Eligibility Chart and Fee Schedule FFY 2026.
• DES CCA-1227A, Maximum Reimbursement Rates for Child Care, effective November 1, 2025.
• Arizona Administrative Code Title 6, Chapter 5, Article 49.
• DES Child Care Provider Registration Agreement CCA-1210B for special-needs definition and enhanced-rate criteria.

Income Eligibility Tests

• Non-enrolled applicants use fee levels L1-L6, corresponding to the initial 165% FPL limit.
• Enrolled recipients use az_ccap_enrolled and may qualify through fee level L7, corresponding to the ongoing 85% SMI limit.
• Family sizes 1-12 use the DES FFY 2026 monthly gross income thresholds.

Eligible Activity

• Employment (full or part-time) qualifies under R6-5-4912(A)(1).
• Education and training qualify an adult only when paired with an average of at least 20 hours/week of work (R6-5-4912(A)(3)); education alone qualifies only teen parents under age 20 (R6-5-4912(A)(4)).
• Inability to provide care (is_disabled) qualifies.

Income Deductions And Exemptions

• Countable income uses PolicyEngine income variables matching R6-5-4914(F) countable income categories, including SSI, railroad retirement, and general assistance.
• A minor student's earnings (wages and self-employment, including SSTB and farm) are excluded (R6-5-4914(G)(13)); lump-sum capital gains from property sales are excluded (R6-5-4914(G)(3)).
• Child support paid for dependents residing outside the household is deducted (R6-5-4914(H)).
• Countable income is rounded down to the whole dollar (R6-5-4914(I)).

Standards And Benefit Calculation

• Copay is a daily per-child amount by fee level and attendance days.
• az_ccap_categorically_eligible (used for both the income-test bypass and the copay exemption) is formula-based from is_tanf_enrolled combined with an employed head/spouse, receives_or_needs_protective_services, and is_in_foster_care.
• az_ccap_special_needs_child is formula-based from eligible child status and is_disabled; the enhanced special-needs rate additionally requires a quality-enhanced (3-5 star / accredited) provider per CCA-1210B.
• Reimbursement uses provider type, child age group, school-age season, quality enhanced rate (+40%), and the flat special-needs rate.

Requirements Coverage

• Covered: Arizona residence, child age, citizenship/qualified-noncitizen status, activity (with the adult education work requirement), initial and ongoing income limits, countable income sources and deductions, family-size thresholds, fee levels, daily copays, formula-based copay exemptions, the categorical without-regard-to-income pathway, provider/age/season rates, quality rate, formula-based special-needs rate, final subsidy formula, and CCDF/state-benefit aggregation.
• Out of scope by user decision: the CDA-only (+35%) enhanced rate and the TCC no-copay-beyond-third-child rule.
• Not modeled: waiting lists, verification workflow, provider contract status, nonpayment sanctions, overpayments, appeals, exact administrative notices, time limits, gambling/lottery income (no PolicyEngine variable), and the Jobs/rehabilitation/court-ordered/shelter activity pathways (employment, education, and inability-to-care are modeled).

Modeling Limitations And Future Work

• Historical backdating. Only the FFY 2026 schedule is modeled (income/fee effective 2025-10-01, rates effective 2025-11-01). As with the other state CCAP implementations, earlier periods back-extrapolate these values rather than using period-correct historical rates, so simulations before late 2025 are approximate. This program may need historical rate/threshold backdating in the future.
• Summer rate test coverage. The school-age summer rate (May-July) is applied correctly inside the monthly calculation and flows through to the annual benefit, but it cannot be asserted in an isolated unit test: mid-year monthly test periods are disallowed (tests use January or whole-year periods) and currently trigger a policyengine-core cache-key issue. The annual total still exercises the seasonal split (verified: a 7-year-old attending a center 10 days/month reimburses $3,300 across 2026 = 9 school-year months at $25/day + 3 summer months at $35/day).

Files

• policyengine_us/parameters/gov/states/az/hhs/ccap/...
• policyengine_us/variables/gov/states/az/hhs/ccap/...
• policyengine_us/variables/gov/states/az/hhs/az_child_care_subsidies.py
• policyengine_us/tests/policy/baseline/gov/states/az/hhs/ccap/...
• policyengine_us/programs.yaml (CCDF state implementation registration)
• changelog.d/8370.added.md

Validation

• policyengine-core test policyengine_us/tests/policy/baseline/gov/states/az/hhs/ccap -c policyengine_us
• make format

Known failing tests: none.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (fa285ae) to head (06c7b6f).
⚠️ Report is 26 commits behind head on main.

Additional details and impacted files

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+ Hits            62       268   +206     

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unittests	100.00% <100.00%> (ø)

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