Document disjoint health premium inputs and correct consumer treatment

[MaxGhenis]

The premium inputs previously left pretax payroll treatment ambiguous. Under the hub's settled disjoint-input contract, a caller supplying $3,000 of non-pretax premiums and $2,000 of pretax payroll premiums paid $5,000 in total. Several benefit consumers counted only the $3,000; this PR counts $5,000 where the program's definition includes both payment methods.

The PR documents the employee premium leaves and the separate employer-paid leaf. It adds pretax payments locally in SPM MOOP, SNAP, HUD, Missouri child care, Pennsylvania child care, Orange County General Relief and New Jersey medical deductions. SSI now excludes qualified cafeteria-plan salary-reduction premiums from wages, without excluding retirement deferrals or reducing self-employment income. North Dakota renter-refund income excludes pretax payments once as excluded income while continuing to deduct unreimbursed medical costs actually paid, including self-employed premiums restored by merged #10055. The CRFB reform is unchanged here; its premium-base change is split into a separate draft PR for Max's methodology decision.

Input contract and invariants

• pre_tax_health_insurance_premiums contains employee premiums paid through pretax payroll deductions. It remains a leaf with no formula and retains main's CMS ESI-premium uprating from #10083.
• health_insurance_premiums, health_insurance_premiums_without_medicare_part_b, other_health_insurance_premiums, reported Medicare Part B and long-term care premium inputs exclude those payroll payments. Applicable non-pretax aggregates and decomposed inputs are alternative representations; their overlapping components must not be added together.
• The pretax and non-pretax sets are disjoint. Total employee-paid premiums equal the applicable non-pretax aggregate plus the separate pretax input. Employer-paid premiums belong in employer_sponsored_insurance_premiums and do not enter employee medical expenses.
• Moving an amount between payment methods leaves spending-based consumers unchanged with eligibility, modeled program premiums and gross income held fixed. Federal taxable/FICA wages, SSI earnings/countable income and ACA/Medicaid MAGI change because tax law distinguishes the methods. SGA retains gross work earnings and remains unchanged. Michigan resources remain unchanged through offsetting wage exclusion and after-tax premium deduction with other benefit amounts held fixed. SSI can rise when wages move to pretax premiums, and SSI enters mi_household_resources; therefore total Michigan resources need not remain fixed when benefits are allowed to respond. North Dakota income remains unchanged through its distinct income-exclusion and medical-expense routes.

The shared medical_expense_health_insurance_premiums formula remains non-pretax. Consumers that count both sets add the separate leaf locally; consumers that exclude pretax keep the shared aggregate alone. Its documentation now makes that choice explicit.

Consumer audit

Round 1 audited main at fe0c3a651cf27a9974074dbbfd5bcac5684c85f2; round 2 audited main at 05907577140ce06f38b45777a05f479181161164 using variable and parameter references, including downstream medical-expense consumers. The initial resolved merge incorporated main de3815f4ccec7c698f4c6c6a5e024acd79f3579b; a second merge incorporates newer fetched main d97b9164c69f3295da44f3ace67985cc5bcf2fbd, including #10055, #10083 and #10097. “Correct” describes this premium contract, not complete coverage of every provision in the program. Derived taxes/benefits inherit the treatment of the listed wage, premium, and expense consumers.

Consumer	Rule	Primary source	Status
Federal taxable wages, pre_tax_contributions; FICA wages, fica_pre_tax_contributions	Qualified payroll premiums excluded once; non-pretax payments do not reduce wages	IRC 125, IRS cafeteria-plan explanation	Correct, unchanged
ACA MAGI and Medicaid MAGI	Follow taxable-income methodology; no additional deduction for ordinary non-pretax premiums	42 CFR 435.603(e), CMS training p106	Correct, unchanged
Shared medical premium resolver	Select direct non-pretax premiums or non-Medicare plus modeled Part B; tax consumers exclude the separate pretax input	IRS medical-expense definition, program-specific sources below	Formula unchanged; documentation clarified
SPM premium aggregate → MOOP → SPM resources	Count employee-paid premiums, including paycheck deductions; exclude employer share	Census SPM documentation p18, ASEC payroll findings pp63–65	Fixed: add separate pretax leaf
SNAP allowable medical expenses	Gross earnings include voluntary pretax reductions; actual insurance premiums have no tax-status exclusion, subject to elderly/disabled medical-deduction rules	7 CFR 273.9(d)(3)(iv), FNS coordination toolkit p47	Fixed: add pretax leaf
HUD medical expenses	Unreimbursed paid/anticipated premiums; HUD bars importing all IRS 502 exclusions	PIH 2023-27 C.3.b p37	Fixed: add pretax leaf
SSI earnings → countable income/deeming; Medicare Savings Programs; optional senior/disabled Medicaid income	Qualified cafeteria-plan salary reductions are not wages; ordinary payroll deductions and retirement deferrals remain wages	SSA POMS SI00820.102 C.2–C.4, retirement earnings rules	Fixed: exclude pretax premiums from wages, capped at wages; preserve parameter-defined other earned sources
Minnesota MSA countable income, gross eligibility, payment and guardian fees	Countable income adopts SSI exclusions; gross income is before deductions/disregards and guardian allowance is capped at 5% of gross income/$100 monthly. Max's d1314 ruling keeps employee salary-reduction premiums in the gross base; retain SSI exclusions for net eligibility/payment	Minn. Stat. 256D.435 subds. 4a, 6, 256D.35 subd. 10, Minn. R. 9500.1206 subp. 15a, 256D.44 subd. 5(d)	Fixed: preserve gross eligibility/guardian treatment while net income inherits SSI exclusion; five integration cases
SSI substantial gainful activity (SGA)	Work earnings retain payroll insurance deductions, unlike SSI countable income	SSA POMS DI10505.010A, 20 CFR 416.974	Preserve gross earnings by restoring only the premium excluded from SSI wages
Medicaid medically needy/209(b) spenddown expenses	SSI income excludes qualified salary reductions; Kansas bars repeating pretax payroll deductions as spenddown expenses. State income/expense methods differ	42 CFR 435.831(b), (d), (e)(1), Kansas §7532.1(4)	Expense formula unchanged; SSI income corrected; state sequencing limitation documented
Missouri CCS adjusted income	Gross income less household-paid insurance premiums, without tax distinction	5 CSR 25-200.050(2), DESE manual §5.7	Fixed: add pretax leaf
Pennsylvania CCW medical expenses → adjusted income	Wages before insurance deductions; unreimbursed premiums allowed subject to medical-expense conditions	55 Pa. Code Ch3042 Appendix A I(A), II(C), PDF pp59,61	Fixed: add pretax leaf
Orange County General Relief countable income	Income diverted to third parties is counted; medical-insurance payments deducted	OC income manual §70.2.a(1), .o(4), .p(1), PDF pp1,4	Fixed: add pretax leaf
New Jersey medical deduction	Salary-reduction premiums taxable in NJ; employee-paid premiums deductible above 2% income	TB-39(R), NJ instructions PDF p25	Fixed: add pretax leaf; preserve merged #10055's exclusion of dependent premiums separately deducted for self-employed coverage; raw wage treatment already correct
North Dakota renter-refund income	Exclude federally/state-excluded income; deduct unreimbursed medical costs actually paid, retaining self-employed premiums excluded from the computed federal subtotal	NDCC 57-02-08.1(5)(c–d), state guidance	Fixed: pretax income exclusion once; preserve merged #10055's paid-cost medical base and caller-supplied subtotal behavior
Michigan household resources	Deduct posttax premiums only; wage source already excludes pretax payroll premiums	Treasury premium FAQ, 2025 instructions p33	Correct, unchanged
Missouri qualified health-insurance subtraction → AGI	Only premiums included in federal taxable income qualify	RSMo 143.121.7, Form 5695	Correct pretax exclusion, unchanged
Ohio medical-insurance helper → insured/uninsured deductions; LTC	Exclude premiums already excluded/deducted in federal/Ohio AGI	ORC 5747.01(A)(10), 2025 worksheet p41	Correct, unchanged
Montana individual/joint medical deductions	Cafeteria-plan premiums ineligible	2022 Form 2 instructions pp26–27	Correct pretax exclusion, unchanged
Washington senior/disabled property-tax deduction sources	Medicare/Medigap/LTC allowed; general private premiums not allowed	RCW 84.36.383(2)	Correct exclusion of aggregate pretax input; no formula change
Alabama medical deduction	Cafeteria-plan premiums ineligible	2024 Form 40 instructions p19	Correct pretax exclusion, unchanged
Arkansas individual/joint medical deductions	Federal medical definition; cafeteria benefits excluded from wages	2024 instructions, IRS Topic 502	Correct pretax exclusion, unchanged
Arizona itemized deductions	Exclude cafeteria premiums unless included in taxable wages	2025 Form 140 booklet p46	Correct pretax exclusion, unchanged
Hawaii medical deduction	Federal IRC medical rules adopted	HRS 235-2.3, N11 instructions pp15–16	Correct pretax exclusion, unchanged
New Mexico medical deduction/exemption/credit	Pretax payroll premiums explicitly ineligible	2022 PIT booklet pp26–27, ADJ6, RC10	Correct pretax exclusion, unchanged
CRFB expanded surtax base	Add employer-provided coverage; employee pretax restoration is a modeling inference from salary-reduction coverage classification	CRFB Break Glass footnote 2, IRS Revenue Ruling 2002-3, PDF pp1–2	Unchanged here; separate PR (#10066)
CBO household market-income additions	Gross wages include employee amounts; add employer-paid premiums only	CBO health-insurance measurement, CBO income definition	Correct, unchanged
Reported Medicare Part B premium input	Non-pretax leaf; no current formula/parameter consumer	Main reference inventory; Medicare/program rules represented by modeled premiums	Documentation only
Federal Schedule A and self-employed health-insurance ALD	Exclude payroll-pretax premiums; payer and SE deduction exclusions owned separately	Schedule A instructions, Form 7206 instructions	Preserve merged #10055: exclude premiums already deducted through the self-employed health-insurance ALD without changing caller-supplied medical subtotals
Idaho premium subtraction	Exclude disjoint payroll premiums from claimant subtraction	Idaho Code 63-3022P, PR #10023 methodology	Out of scope; no Idaho formula edits

Minnesota MSA methodology. Max ruled in d1314 (2026-10-11): keep the pre-tax premium in MSA gross income, as main does; Minn. Stat. 256D.35 subd. 10. The statute defines gross income before deductions and disregards. This ruling selects the implemented treatment of an employee's cafeteria-plan premium and closes the methodology item from hub review r2.

Rule 9500.1206 primarily governs General Assistance under 9500.1200; Combined Manual 0017 adopts GA gross-income conventions for non-SSI MSA recipients and substitutes the full federal benefit rate for SSI recipients. Under Max's ruling, the gross eligibility test and guardian-fee base restore the employee salary reduction excluded from SSI wages, preserving main's treatment of the person's own gross wages. 256D.435 continues to supply SSI exclusions for net eligibility and payment. No MSA code or expectation reversion was required when merging main.

In the first new MSA fixture, gross income remains $1,950 ($1,700 gross wages + $250 Social Security), the guardian allowance is $97.50 (5% of $1,950), and MSA is $155 ($1,055 + $97.50 - $997.50 countable income). Excluding the premium from gross would instead produce $1,850, $92.50 and $150; d1314 selects the former treatment. The separate SSI wage exclusion remains in the net calculation.

Medically needy eligibility currently models ABD applicants using SSI countable income. This PR retains the non-pretax-only medical expense aggregate to avoid a blanket second deduction after correcting SSI wages. Kansas explicitly prohibits that repetition. Utah allows employee payroll premiums, paired with gross-income payroll rules. The audit does not establish a universal federal exclusion of pretax premiums as expenses. State-specific sequencing remains a limitation of the existing annual proxy; IRS employer-provided tax classification alone does not establish third-party payment for Medicaid.

The audit also noted pre-existing limits unrelated to this contract: Montana's premium/floor treatment, Washington's unmodeled Medigap component, New Mexico's federal-itemization adjustment, and Alabama's separate small-business insurance deduction. They are reported here without expanding this patch.

Round 2

Removed the CRFB parameter/test changes from this PR in an additive revert commit and opened #10066 from current main. That draft separates the definite after-tax double count from the choice to restore qualified employee salary reductions. Added 16 integration cases: two MSP, two student, one child allocation, SSI spouse/parent deeming, optional Medicaid spouse/parent deeming, two Connecticut SSP, and five Minnesota MSA. Parental fixtures assign singleton marital units to unmarried people and assert zero spousal deeming. The Hypothesis property now includes one-person and two-person married units in every state/example and freezes SSI payments for the Michigan spending invariant. MSA gross eligibility and guardian fees now restore the capped wage exclusion; net eligibility/payment retain it. Medicaid spenddown sequencing remains limited as described above.

Validation

Final merge head: b5a0b3cc588d95f00768d6e664e3d3075f851313, incorporating newer fetched main d97b9164c69f3295da44f3ace67985cc5bcf2fbd.

The first resolved merge head d939e639e39ed331f842e8b06c920fd111d1b121 (main de3815f4ccec7c698f4c6c6a5e024acd79f3579b) passed all 25 requested and adjacent files: 117 YAML cases and 57 pytest cases. This covers every one of the PR's 21 changed test files relative to the original merge base, all conflicted/adjacent YAML files, the new premium-input property, and the existing ESI uprating, SE premium conservation and Schedule A pretax properties.

Main advanced during validation. A read-only dependency audit confirmed that all 47 original PR test/variable paths remain unchanged and the fixtures supply premium amounts at their test period. The additional CMS MOOP uprating change is covered on the final merge tree by test_cms_moop_uprating.py: 58 passing parameter/metadata tests, including the changed extension helper and input routing. No repeat of unaffected files was needed. Across both merge steps, all 26 files passed (232 cases total). The table's first 25 rows ran on the first merge head; its final row ran on the final merge tree.

Each file ran directly in a separate foreground process, sequentially, using Python 3.13.9 and PolicyEngine Core 3.33.2. All runs set OMP_NUM_THREADS=4 OPENBLAS_NUM_THREADS=4 MKL_NUM_THREADS=4 VECLIB_MAXIMUM_THREADS=4 NUMEXPR_NUM_THREADS=4 OMP_WAIT_POLICY=PASSIVE and PYTHONPATH to this checkout. YAML used python -m policyengine_core.scripts.policyengine_command test <file> -c policyengine_us; Python used python -m pytest -q <file>. No folder run, microsimulation or parallel heavy test process was used. make format and the PR diff against main's git diff --check passed.

Test file (under policyengine_us/tests/)	Passed
policy/baseline/gov/states/nd/tax/property/renters_refund/nd_renters_refund_income.yaml	14
policy/baseline/gov/states/nj/tax/income/deductions/nj_medical_expense_deduction.yaml	13
policy/baseline/household/expense/health/medical_expense_health_insurance_premiums.yaml	2
policy/baseline/gov/hhs/medicaid/eligibility/categories/medically_needy/medicaid_medically_needy_medical_expenses.yaml	3
policy/baseline/gov/hhs/medicaid/income/deemed/from_ineligible_parent/medicaid_optional_senior_or_disabled_unearned_income_deemed_from_ineligible_parent.yaml	4
policy/baseline/gov/hhs/medicaid/income/deemed/from_ineligible_spouse/medicaid_optional_senior_or_disabled_income_deemed_from_ineligible_spouse.yaml	4
policy/baseline/gov/hhs/medicare/savings_programs/income/msp_countable_income.yaml	5
policy/baseline/gov/hud/hud_medical_expenses.yaml	3
policy/baseline/gov/local/ca/oc/general_relief/income/ca_oc_general_relief_countable_income_person.yaml	6
policy/baseline/gov/ssa/ssi/eligibility/income/deemed/from_ineligible_parent.yaml	4
policy/baseline/gov/ssa/ssi/eligibility/income/deemed/from_ineligible_spouse.yaml	4
policy/baseline/gov/ssa/ssi/eligibility/income/deemed/ssi_ineligible_child_allocation.yaml	2
policy/baseline/gov/ssa/ssi/eligibility/income/ssi_blind_or_disabled_working_student_exclusion.yaml	10
policy/baseline/gov/ssa/ssi/income/ssi_earned_income.yaml	9
policy/baseline/gov/ssa/ssi/income/ssi_engaged_in_sga.yaml	6
policy/baseline/gov/states/ct/dss/ssp/premium_input_contract.yaml	2
policy/baseline/gov/states/mn/dhs/msa/premium_input_contract.yaml	5
policy/baseline/gov/states/mo/dese/ccs/income/mo_ccs_adjusted_income.yaml	5
policy/baseline/gov/states/pa/dhs/ccw/pa_ccw_adjusted_income.yaml	7
policy/baseline/gov/usda/snap/income/deductions/snap_allowable_medical_expenses.yaml	3
policy/baseline/household/income/spm_unit/spm_unit_medical_out_of_pocket_expenses.yaml	6
core/test_esi_premium_uprating.py	50
core/test_medical_expense_premium_conservation.py	5
core/test_schedule_a_pre_tax_premium_invariants.py	1
core/test_premium_input_contract.py	1
core/test_cms_moop_uprating.py	58

Python file	Local elapsed seconds	Peak RSS (GiB)
test_esi_premium_uprating.py	684.31	0.80
test_medical_expense_premium_conservation.py	438.07	0.93
test_schedule_a_pre_tax_premium_invariants.py	155.24	0.93
test_premium_input_contract.py	110.32	1.10
test_cms_moop_uprating.py	241.74	0.80

The new test_premium_input_contract.py property checks generated transfers between disjoint employee payment methods, eight generated plus two explicit examples, across singleton and married-couple units in seven states. It uses the shared read-only reference system and fresh paired synthetic simulations for isolation, with no dataset load or repeated full-model construction. These measured costs include process/model startup on the contended local macOS machine and do not estimate incremental Linux CI group cost. The other four Python files already exist on main and verify preservation of main's uprating and Schedule A/SE premium behavior. This PR adds no CI jobs or runners.

The first ND run passed all 14 cases; its external /usr/bin/time -l resource reporter then failed because the sandbox denied sysctl kern.clockrate. The raw passing test output is preserved, and its RSS is unavailable. Later files used a sandbox-compatible per-child resource measurement. No failing policy behavior was concealed or expectations rewritten.

The round-1 run passed 81 YAML cases across 12 files (38 added and 43 preserved) before the CRFB split, plus the original one-person property. The revised property retains eight generated examples and two explicit examples. Every changed YAML file is run directly, foreground, one at a time. The Python property exercises generated premium transfers rather than duplicating the policy formulas; explicit examples cover zero, complete transfer, and no transfer. Frozen eligibility/program premiums isolate payment treatment from legitimate MAGI-induced coverage changes. The Kansas spenddown case starts from raw wages of $27,020, age 65 and $4,000 of pretax premiums, and verifies SSI earnings of $23,020 and countable income of $11,000. It explicitly disables the separate SSI-recipient Medicaid pathway, so its eligibility assertion detects an erroneous second premium deduction.

No partner files are edited. Read-only inventory found 144 partner YAML files, no pretax or employer-paid inputs, and only zero direct-premium inputs. No relevant partner output movement is expected from those facts; partner scenarios are not rewritten to make the model pass.

The property belongs to the existing Rest/core CI subgroup; no jobs or concurrency are added. Baseline successful main Rest/core at the previously audited main commit ran 830 tests with external elapsed 681.09 seconds and peak RSS 6,756,660 KiB (6.44 GiB). The new file did not exist on main, so its standalone baseline file cost is zero. The round-1 property's standalone run took 901.06 seconds including process/model startup and peaked at 3,317,071,872 bytes (3.09 GiB RSS) on the contended local macOS machine, with one math-library thread. Pytest reported 720.09 seconds. These local measurements are not an estimate of incremental Linux subgroup cost; updated Linux group time/memory remains for hub/CI validation.

Changelog: changelog.d/hub-premium-input-contract-1010.fixed.md.

axiom: TheAxiomFoundation/rulespec-us#1706 TheAxiomFoundation/rulespec-us#1714 TheAxiomFoundation/rulespec-us#1358 TheAxiomFoundation/rulespec-us#1654 TheAxiomFoundation/rulespec-us#1732 TheAxiomFoundation/rulespec-us#1733 TheAxiomFoundation/rulespec-us#1734 TheAxiomFoundation/rulespec-us#1735 TheAxiomFoundation/rulespec-us#1736 TheAxiomFoundation/rulespec-us#1737 queued

Maintainer Axiom follow-up is required. The signed encoder is not available in this workspace; no billed encoder run was requested or performed. The primary provisions and companion tests are listed above.

Merge with main

Merged main de3815f4ccec7c698f4c6c6a5e024acd79f3579b into hub-premium-input-contract-1010 with a merge commit, then incorporated newer fetched main d97b9164c69f3295da44f3ace67985cc5bcf2fbd in a second merge commit. #10055 is included in main and this merge. Its self-employed premium exclusions and paid-cost handling are retained alongside this PR's disjoint-input contract.

Shared path	Merged #10055 behavior	Combined behavior
policyengine_us/variables/gov/states/nj/tax/income/deductions/nj_medical_expense_deduction.py	Remove each dependent's separately deducted SE premiums from general medical expenses	Retain that exclusion and add disjoint pretax payroll premiums
policyengine_us/tests/policy/baseline/gov/states/nj/tax/income/deductions/nj_medical_expense_deduction.yaml	Four SE attribution cases	Keep those cases, this PR's four payment-method cases, and one combined SE/pretax case
policyengine_us/variables/gov/states/nd/tax/property/renters_refund/nd_renters_refund_income.py	Use medical costs actually paid, retaining SE-ALD premiums when excluded from a computed federal subtotal; preserve supplied subtotals	Retain paid-cost and supplied-subtotal behavior and exclude disjoint pretax premiums from raw income once
policyengine_us/tests/policy/baseline/gov/states/nd/tax/property/renters_refund/nd_renters_refund_income.yaml	Six paid-cost and supplied-subtotal cases	Keep those cases, this PR's four payment-method cases, and one combined SE/pretax case

Two new combined YAML cases exercise nonzero SE deductions and pretax premiums together: ND $40,000 - $3,000 - ($5,500 + $1,000) = $30,500; NJ $1,000 + $5,500 + $3,000 - $800 = $8,700. Existing cases and expectations from both branches are retained unchanged.

The combined NJ medical base is itemized_medical_expenses - excluded_dependent_premiums + pretax premiums. The combined ND calculation subtracts pretax premiums once and subtracts itemized_medical_expenses + itemized_medical_expenses_applied_exclusion, preserving #10055's distinction between a computed federal subtotal and a caller-supplied subtotal.

#10083, commit 35f3c1f92a, uprates both employee pretax and employer-paid ESI premiums by CMS ESI premium per enrollee. The resolved input documentation retains that uprating and its fixed coverage/share assumptions while stating that employee and employer payments are disjoint. #10097, commit bee8954716, uprates HSA payroll contributions by the IRC 223(b)(2) contribution limit; this merge retains that behavior.

Main advanced while the original sequential validation was running. Its five additional commits include #10084, the CMS out-of-pocket uprating refresh, plus state-credit and CI/publishing updates. They change none of the original PR's 21 test files or 26 variable files. Existing premium fixtures supply inputs at the test period, so the revised MOOP uprating does not alter those explicit amounts. The merge retains these main changes and adds a targeted run of the 58-case CMS MOOP parameter file; that file also checks the changed extension helper without constructing a microsimulation.

The NJ and ND YAML files and affected premium properties are included in the merge validation recorded above. Minnesota gross treatment remains as selected in d1314.

Merge with main (2)

Merged main f4539bc050400372ac2a4a8634b7df70c9a960bf in merge commit 138dd41db27eee29e28f93b7a7d4d8d298c30f47. The conflicts in health_insurance_premiums_without_medicare_part_b.py and long_term_health_insurance_premiums.py keep this PR's disjoint-input documentation plus #10085's unchanged comments and uprating (CMS ESI premium per enrollee and CPI-U medical care, respectively). The three clean premium-file merges retain both sides' changes: direct-purchase, Part B and ESI series alongside this PR's documentation. No additional formula or uprating change was introduced.

Checked #10055's payer attribution, bounded SE exclusions, paid-cost restoration and supplied subtotals against the consumers and combined ND/NJ cases; checked #10085's cross-year ESI movement assertions against this PR's same-year premium-transfer contract. No contradictory assertions were found.

All 24 required files passed: 219 Python + 115 YAML = 334 tests, one file per foreground process, sequentially, with all required thread caps. This covers all 21 PR-changed test files plus premium uprating (155), conservation (5), and CMS MOOP (58). Main already includes #10221, so the formerly stale CMS expectation passes unchanged. make format and diff whitespace checks passed.

The PR delta against the new merge base has the same 48 paths and identical ordered additions/deletions as d97b9164c6..b5a0b3cc58; its substance is unchanged. The zero-impact measurement above remains tied to its recorded old base/head; no microsimulation was rerun. Main advanced during validation to a2f63c1235 (#9913 plus a version update); its 11 paths do not overlap this PR. These tests cover the f4539bc050 merge tree.

Hub microsimulation impact (current head)

A real microsimulation on the default dataset, main at the merge base f4539bc050 against this PR's head 138dd41db2, for 2025 and 2026. The runs went one at a time under the shared heavy-job lock. Sums are weighted.

Output	2025 change	2026 change	2025 records changed (weighted)	2026 records changed (weighted)
ssi	+0	+0	0 (0)	0 (0)
ssi_countable_income	+0	+0	0 (0)	0 (0)
medicaid_household_income	+0	+0	0 (0)	0 (0)
mn_msa	+0	+0	0 (0)	0 (0)
ct_ssp	+0	+0	0 (0)	0 (0)
mi_household_resources	+0	+0	0 (0)	0 (0)
msp_countable_income	+0	+0	0 (0)	0 (0)
snap	+0	+0	0 (0)	0 (0)
snap_allowable_medical_expenses	+0	+0	0 (0)	0 (0)
hud_medical_expenses	+0	+0	0 (0)	0 (0)
nd_renters_refund	+0	+0	0 (0)	0 (0)
nj_medical_expense_deduction	+0	+0	0 (0)	0 (0)
spm_unit_medical_out_of_pocket_expenses	+0	+0	0 (0)	0 (0)
ca_oc_general_relief	+0	+0	0 (0)	0 (0)
mo_ccs	+0	+0	0 (0)	0 (0)
pa_ccw	+0	+0	0 (0)	0 (0)
state_income_tax	+0	+0	0 (0)	0 (0)
income_tax	+0	+0	0 (0)	0 (0)
household_net_income	+0	+0	0 (0)	0 (0)
household_benefits	+0	+0	0 (0)	0 (0)

No record changes in either year across all 20 outputs, as at the earlier head b5a0b3cc58. That matches the dataset check: neither DEFAULT_DATASET at main nor the certified populace-us-2024-spm-20260909 build (revision 9a814a3b3b) has a pre_tax_health_insurance_premiums column, and the variable has no formula, so the baseline pre-tax additions and exclusion are zero on the pinned dataset. The split CRFB draft changes its premium addback sources and is checked in that PR.

Comparison files are in fixes/10046-impact/ on the hub host.

[MaxGhenis]

Cross-repo note for the hub, from the session behind #10067. No change requested on this PR.

A producer for the pre-tax input is coming. PolicyEngine/microcosm#1189 as opened wrote the reported premium (PHIP_VAL, about $181B) to pre_tax_health_insurance_premiums and left the same dollars in health_insurance_premiums_without_medicare_part_b, which breaks the disjoint contract this PR documents. I raised it there. Its session agrees with the contract and has told me it will:

• ship only employer_sponsored_insurance_premiums in microcosm#1189;
• add the pre-tax column in a follow-up that nets it out of the non-pre-tax premium outputs, with a release gate that stays red until the pinned engine counts the pre-tax input in SPM medical out-of-pocket expenses.

So this PR is a prerequisite for that data. The "no pre_tax_health_insurance_premiums column" finding under "Hub microsimulation impact" holds for the pinned dataset, but will stop holding once the follow-up ships. #10064, which asked for an engine subtraction on Schedule A, is closed as not planned.

One point for the audit, relayed from that session. On Microcosm's PUF-support rows the non-pre-tax premium is not PHIP_VAL. puf_support.py sets health_insurance_premiums_without_medicare_part_b to 45.3% of PUF E17500 (_PUF_MEDICAL_EXPENSE_CATEGORY_BREAKDOWNS, lines 603–607 and 4273–4276 at 6f727eac), or to a QRF draw. So person-level disjointness against a carried pre-tax premium can be asserted only on measured ASEC rows. I confirmed the constant and its use; I did not trace the QRF path.

#10067 adds federal Schedule A tests under this contract: eight YAML cases in itemized_medical_expenses.yaml and a Hypothesis property test. It changes no formula and shares no file with this PR, #10055 or #10023. Both files pass on this branch at de43bf5f61; the two SSI deeming cases added since do not touch the federal path.