Count property tax billed in another household member's name as rent in Montana's elderly homeowner/renter credit (ARM 42.4.302(2)(b)) by MaxGhenis · Pull Request #9945 · PolicyEngine/policyengine-us

MaxGhenis · 2026-10-06T22:34:47Z

Summary

An elderly Montanan living rent-free in a home billed to another household member got $0 from the elderly homeowner/renter credit. The typical case is an adult child who files separately. Montana lets that claimant count the property tax as rent:

ARM 42.4.302(2) ("IMP: 15-30-2340, 15-30-2341"): "To calculate the credit, an eligible claimant may use property taxes billed: ... (b) as rent if the property occupied by the claimant is in a name other than the claimant."
Before the rule's 2017 restructuring (2017 MAR p. 2092), the same text was ARM 42.4.302(5), in force from 8/20/2004: "Property taxes billed are allowable as rent if the property occupied by an eligible claimant is in a name other than the claimant." See the mtrules.org captures of 2008, 2010, 2017 and 2018.
The Form 2 instructions for Schedule 2EC line 23 (2025, PDF p. 47): "If the property occupied by you is in a name other than your own, the property taxes billed for that property can qualify as rent only."

The model counted only each tax unit's own real_estate_taxes and rent, so that claimant's lines 23 and 24 were both 0. This PR follows #9900 (one claimant per household), which has merged; main is merged in.

The homestead reading (decision d1035) is not implemented

d1035 is still open. It asks whether the household's one claimant counts the homestead's whole property tax and rent (MCA 15-30-2337(5), (10)) or only their own (the form's "you"). This PR keeps the form reading, which is the decision's default.

The rule here is needed under either ruling. §2340(1) and (2) cover a claimant who owns or rents the homestead; a claimant who does neither needs ARM 42.4.302(2)(b) to count the bill at all.

d1035 would still change two things here:

A claimant who co-owns the home with someone in another tax unit counts only their own bill on line 23 today. Under the homestead reading they would count the whole bill.
That would remove the intended exception under the invariants below.

I added both points to d1035.

How "as rent" enters Schedule 2EC

Line	Before	After
23 Property tax billed	`real_estate_taxes` of everyone in the tax unit	unchanged (now the variable `mt_elderly_homeowner_or_renter_credit_property_tax_billed`)
24 Rent paid	`rent` of the tax unit	the same, or, when line 23 is 0, the larger of that and the household's `real_estate_taxes` (new `mt_elderly_homeowner_or_renter_credit_gross_rent`)
25	line 24 × 15%	unchanged

Choices, with reasons:

The bill goes on line 24 and is multiplied by 15% on line 25. The instructions put the sentence under line 23 and say the bill "can qualify as rent only", so it may not go on line 23. The rule called it "allowable as rent". Line 24 is rent, line 25 is "Multiply line 24 by 15%", and the 15% is §2337(11)'s rent-equivalent tax.
Line 24 is the larger of the rent paid and the bill, not their sum. The rule says the claimant "may use" the bill. I read that as a choice between two measures of what it costs to occupy one home, and adding them would count that home twice. Max asked me to decide how the bill enters lines 24 and 25.

One alternative is also defensible: use the bill only when the claimant pays no rent. §2337(5) defines gross rent as rent "actually paid ... pursuant to an arm's-length transaction". The two readings differ only for a claimant who pays a household member less rent than that member's bill. Both are recorded on d1035.
The rule applies when no one in the tax unit is billed. Line 23 stays as on main: the tax unit's real_estate_taxes, a dependent's included. real_estate_taxes is an expense amount, not a record of title; of the 17,216 person records with real_estate_taxes in the microdata, 14,767 are the household's reference person, and that person can be a tax unit dependent. So the model cannot tell a home wholly in a dependent's name, and keeps a dependent's bill on the claimant's line 23.

An earlier version moved a dependent's bill to line 24. Sol's review r2 flagged that, and the 2024 run showed its cost: it cut one Montana tax unit's credit from $646 to $0, −$1.35M weighted. In that tax unit the 68-year-old reference person holds the bill and is a dependent of an 85-year-old head.
The bill is the household's whole property tax. The instructions refer to "the property taxes billed for that property", so every other member's bill counts, a spouse's or dependent's in another tax unit included. PolicyEngine's household is one dwelling. Owners outside the household, such as a landlord, are not visible to the model.
Every modeled year. The rule has been in force since at least 8/20/2004, as (5) and then (2)(b), so it applies from 2009 and needs no parameter.

The instructions caught up later. The 2009 and 2010 booklets mention only trusts ("Property tax that is billed to an irrevocable or family trust qualifies as rent only"). The general sentence appears from 2011.

A tension the PR does not resolve. §2338(1)(c) makes eligible a person who occupied a dwelling "as an owner, renter, or lessee", and the 2025 Schedule 2EC has the same checkbox. A rent-free occupant fits that only through the rule's treatment of the bill as rent. Max's request named this case, the elderly parent in an adult child's home, as the gap to close, and the department's instructions apply the rule. So the PR models it. The tension is recorded on d1035.

Example: 2024, a parent living in an adult child's home

The parent is 80, has a $14,000 pension and pays no rent. The child is 45, has $6,000 of interest and is billed $4,000 of property tax. Each files their own return.

2024 Schedule 2EC line	Parent, before	Parent, after
18 Gross household income	20,000	20,000
20 = 18 − 12,600	7,400	7,400
22 Net household income (× 0.035)	259	259
23 Property tax billed	0	0
24 Rent	0	4,000
25 = 24 × 15%	0	600
27 = 23 + 25 − 22	0	341
30 Credit (× 100%)	0	341

The child is under 62 and cannot claim.

If the parent paid the child $2,400 of rent, line 24 would still be 4,000. Counting the rent alone would give 101.
If the parent paid $6,000, line 24 would be 6,000 and the credit 641, not 4,000 + 6,000.

Changes

New mt_elderly_homeowner_or_renter_credit_property_tax_billed (TaxUnit, line 23): adds = ["real_estate_taxes"], as main computed it inline.
New mt_elderly_homeowner_or_renter_credit_gross_rent (TaxUnit, line 24).
- It sums the household's bill as tax_unit.sum(add(person.household, period, ["real_estate_taxes"]) * head).
- It is vectorized, with no Python branching on arrays.
mt_elderly_homeowner_or_renter_credit_pre_one_claimant reads the two variables; the rest of its computation is main's.
mt_elderly_homeowner_or_renter_credit_selected_claimant is unchanged apart from its comment. One claim per household is still paid: a claimant whose bill counts as rent competes with the household's other eligible tax units by credit.

Tests

New mt_elderly_homeowner_or_renter_credit_gross_rent.yaml, 14 cases:
- rent only;
- a parent in a child's home;
- a claimant billed their own tax;
- rent below the bill;
- rent above the bill;
- a dependent's bill, which stays on line 23;
- two co-owners;
- a joint couple billed through the spouse;
- 2009;
- outside Montana;
- a joint couple billed nothing (the bill counts once);
- a home co-owned with a dependent;
- rent paid by a dependent;
- a bill held by another tax unit's spouse.
New mt_elderly_homeowner_or_renter_credit_property_tax_billed.yaml, 7 cases, including fractional bills.
mt_elderly_homeowner_or_renter_credit.yaml, 8 new end-to-end cases with Schedule 2EC line-by-line comments:
- the example above;
- rent below the bill;
- rent above the bill;
- two elderly siblings where one owns: one claim of 1,150, [0, 1_150];
- a dependent's bill: 1,150, as on main;
- a home co-owned with a dependent: 1,150, as on main;
- rent paid by a dependent: 900;
- a bill held by the spouse on a child's joint return: 600.
Unmarried people each have their own marital unit and the married couple shares one, and SSI is pinned at 0 to isolate the credit's arithmetic. Without separate marital units, two elderly siblings form a default SSI couple.
mt_elderly_homeowner_or_renter_credit_pre_one_claimant.yaml, 2 new cases, set up the same way.
test_mt_elderly_credit_one_claimant.py:
- Its Schedule 2EC reference applies the rule, and 2 pinned Hypothesis examples were added.
- A worked example.
- A new Hypothesis test of monotonicity (invariants 6 and 7).
- A pinned test of the one intended exception.
These add about 4 s of test time to that file. Local run on macOS at load ~35: 38.9 s wall and 1.47 GB peak RSS for the whole file, including the model import. This is not a Linux CI measurement. No new test file.

Run locally against the final tree, one file at a time:

All 13 elderly-credit YAML files pass.
test_mt_elderly_credit_one_claimant.py (5 tests) and test_mt_elderly_credit_household_members.py (3 tests) pass, with Hypothesis installed.
test_reference_urls and test_no_concatenated_reference_urls pass.

Reviews

In-session checks on the first version (arithmetic, mutation testing, legal reading, code). They found that the rule predates 2011, which removed the 2011 parameter, and that a dependent co-owner's bill had stopped counting. Both are fixed.
Sol r2, at a93de09280: REQUEST_CHANGES. One major finding: a bill on a dependent does not show title. Three minor ones: an implicit SSI couple, unqualified invariants, and untested dependent-paid rent. All four are fixed in 88a93c5652.
Sol r3, at 88a93c5652: APPROVE. It recomputed 28 cases (88 assertions) independently and ran the credit YAML (49 passed), the gross-rent YAML (13) and the Python file (5). Its non-blocking findings were a spouse-held-bill aggregation case and a stale PR description, with fractional bills as an optional extra. The tests are added in c03d028f6e and the description is rewritten.
Sol r4, at c03d028f6e: APPROVE. It recomputed the three new cases and checked this description against the code, tests and impact outputs. Its minor wording fixes are applied here.

Invariants

These hold for every Montana household. The first five are #9900's; the Hypothesis tests check all seven.

Each tax unit's credit before the limit equals a reference written from the Schedule 2EC lines, including this rule.
The household's credit is the largest of its tax units' credits, and never exceeds the $1,150 cap.
At most one tax unit per household is paid.
Each tax unit is paid nothing or its whole credit.
The household's credit does not depend on the order of its tax units.
Holding household income and refundable credits fixed, raising the property tax billed to one tax unit never lowers another tax unit's credit before the limit. It never lowers its own credit either, if it was already billed property tax.
Holding household income and refundable credits fixed, raising a bill that was already positive never lowers the household's credit.

Household income has to be held fixed because, in general, a larger property tax deduction can change a refundable credit and so gross household income (line 8), which moves every tax unit's line 22. The generator has no earned income or other deductions, so it holds that fixed.

Intended exception to 6 and 7. A tax unit billed nothing that becomes billed a small amount can lose credit. It stops counting the household's bill as rent and counts only its own bill on line 23. In the example, billing the parent $100 drops their credit from 341 to 0.

This follows from the form reading of line 23 for a co-owner in another tax unit. It is pinned by test_newly_billed_tax_unit_can_lose_credit. Under d1035's homestead reading a co-owner would count the whole bill, and the drop would go away.

Microsim impact

No change in 2024 or 2026. I ran full-population microsimulations of main (5ec60b209a) and of this PR's model code (88a93c5652; the later commit adds tests only) through the hub runner lockrun.sh. Both used the default dataset (populace_us_2024, tag populace-us-2024-spm-20260909).

	2024 main	2024 PR	2026 main	2026 PR
Montana elderly credit	$6,479,276	$6,479,277	$6,335,598	$6,335,598
Records with a positive credit	13	13	10	10
Records whose credit changed by more than $0.005		0		0

The $0.38 and $0.22 weighted differences are float32 noise; no record moves by half a cent.

The rule does reach the data. Five eligible Montana tax units (4,603 weighted in 2024, 4,679 in 2026) are billed nothing while another member of their household is billed. None gains, because each household's gross household income is between $58,391 and $409,992 in 2024. That is above the $45,000 limit, so line 29 is 0%, and line 22 already exceeds 15% of the bill. The rule pays only lower-income households, such as the example above, and the sparse sample has none of them in Montana.

The earlier version's impact. A version that moved a dependent's bill to line 24 changed one record in 2024, cutting its credit from $646 to $0 (weight 2,091, −$1.35M). That is choice 3 above. Run outputs, the per-record analyses and the launch scripts are in ~/reviews/mt-ehrc-property-in-others-name-2026-10-06/impact/ (analysis-r2-2024.txt, analysis-r3-2024.txt, analysis-r3-2026.txt).

Not changed

Decision d1035, described above.
Owners outside the household. The model sees property tax only for household members. A claimant who lives rent-free in a home owned by someone outside the household is not modeled.
Primary residence and one acre. real_estate_taxes is not limited to the residence and one acre. This was already true of line 23; the rule now passes it to line 24 as well.
An elderly dependent as claimant. Eligibility still checks only the tax unit head and spouse (predates Limit the Montana elderly homeowner/renter credit to one claimant per household (MCA 15-30-2341(1)) #9900).

axiom: TheAxiomFoundation/rulespec-us#1512 queued (ARM 42.4.302(2)(b) evidence, review_finding addendum and companion cases in this comment; signed-encoder runs need approval and ARM 42.4.302 and the Montana forms are not in the pinned corpus)

🤖 Generated with Claude Code

… the forms - Federal income tax deduction (through 2023): attribute federal tax to the spouse who earned the income and cap each spouse at $5,000, instead of prorating the jointly capped amount by Montana AGI (2022 Form 2 instructions, Itemized Deductions Schedule, line 4). - Child and dependent care expense deduction (through 2023): phase out on the couple's combined Montana AGI and split the result equally only for spouses filing separately on the same form; a single filer and a joint return take the whole deduction (Form 2441-M lines 3-7). - Elderly homeowner/renter credit: count federal AGI without regard to losses (MCA 15-30-2337(9)(a); Form 2EC line 9). Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

…ions Each spouse filing separately on the same form deducts their own federal income tax up to $5,000, so both spouses itemize and Montana tax is 6,295.56. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

…chedule - A married person filing on a separate form (federal filing status SEPARATE) cannot take the child and dependent care expense deduction: "married couples shall file a joint return or file separately on the same form" (MCA 15-30-2131(1)(c)(vi)(A)); 2022 instructions, line 14. - The 2023 credit schedule was the Elderly Homeowner/Renter Credit Schedule; it became Schedule 2EC in 2024. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

MCA 15-30-2337(4) defines gross household income as "all income received by all individuals of a household while they are members of the household". The 2023 Elderly Homeowner/Renter Credit Schedule combines the returns of "ALL members of the household" (lines 1-7 and 9) and has non-filing members report their wages on line 8; the 2024 and 2025 Schedule 2EC put "Income received by other members of your household" on line 17. The model summed each person's federal AGI over the tax unit. A tax unit dependent's federal AGI is zero (their income is on their own return), so a dependent's wages and other income were left out, and household members who file their own returns were never counted. - Add dependent_gross_income to the gross income sources. It counts a dependent's gross income items, gains but not losses, and the taxable part of their Social Security; the formula now subtracts that part before adding the untaxed remainder, so the benefits count once. - Sum gross household income over the household instead of the tax unit in the net household income and the credit. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

… tests dependent_gross_income counts anyone who is not the head or spouse, while irs_gross_income counts anyone who is not a dependent. A person with neither role (a minor alone in a tax unit whose dependent flag is input as false) was counted by both. Count dependent_gross_income in the formula for tax unit dependents only, so the two paths split people exactly. The property tests check, for random claimants and household members, that gross household income is the Schedule 2EC total whether the other member is a dependent or files their own return, that the credit is the same either way, stays within its bounds, and never rises with income. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

… household MCA 15-30-2341(1): "Only one claimant per household in a claim period ... is entitled to relief." Since gross household income now counts every household member, two eligible tax units in one household (for example two elderly siblings filing separately) each computed a credit on the same household income and both were paid. - mt_elderly_homeowner_or_renter_credit_pre_one_claimant holds the existing computation (Schedule 2EC lines 18-30) for every eligible tax unit. - mt_elderly_homeowner_or_renter_credit_selected_claimant (TaxUnit) ranks the eligible tax unit heads within each household by that credit with get_rank and selects the largest; ties keep member order, so exactly one tax unit per household with an eligible one is selected. - mt_elderly_homeowner_or_renter_credit pays only the selected tax unit. Six legacy credit cases that never set a state now place their households in Montana. Adds YAML cases (two eligible tax units, one eligible, a joint couple, a tie, separate households) and property tests against a Schedule 2EC reference. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

- Cite ARM 42.4.302, the rule implementing 15-30-2341, in the selected claimant's references; note that neither it nor the statute says which member claims. - Restore the living-apart note in the net household income comment with its source (ARM 42.4.302(3)(a)), and say in the selection comment that a separated spouse in another tax unit is not linked, so that limit is not modeled. - Selected-claimant Case 8 now fails if non-heads are ranked: a dependent's input amount larger than the other tax unit's no longer decides the selection. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Independent review (Opus) asked for text fixes only: - The selection ranks by Schedule 2EC line 26 (property tax billed plus 15% of rent, before the cap), not by total housing cost; say so. - Counting each tax unit's own property tax and rent follows the form's wording; the statute defines both for the homestead (MCA 15-30-2337(5), (10)). Name that reading as not modeled (queued for a ruling as decision d1035). - Uniqueness of the selection comes from get_rank's ranks; its stable sort only breaks ties. - Cite ARM 42.4.302 at Cornell, which shows the rule text. The Hypothesis test is now derandomized and pins a tie at the cap and an owner against a renter who pays more but has the smaller line 26. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

…ructions Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Retain refundable-credit and actual-receipt income rules, dependent-owned non-loss deductions, and federal-AGI tax allocation alongside maximum-credit claimant selection and the negative-income multiplier fix. Preserve both test sets and add a worked combined-credit regression.

…derly credit ARM 42.4.302(2)(b) lets an eligible claimant use property taxes billed "as rent if the property occupied by the claimant is in a name other than the claimant"; the Form 2 instructions (line 23, since tax year 2011) say such taxes "can qualify as rent only". The model counted only each tax unit's own property tax and rent, so an elderly person living in a home billed to another household member got $0. - New mt_elderly_homeowner_or_renter_credit_property_tax_billed (Schedule 2EC line 23): the property tax billed to the tax unit's head and spouse. A dependent's bill is in a name other than the claimant's. - New mt_elderly_homeowner_or_renter_credit_gross_rent (line 24): rent paid, or, for a tax unit billed no property tax, the larger of that and the household's property tax. Line 25 then takes 15% of it. - New parameter property_tax_in_another_name_as_rent: false for 2009-2010, whose instructions applied "rent only" just to trusts; true from 2011. - The pre-limit credit reads both; the one-claimant selection is unchanged. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

…line 23 Review fixes for the property-tax-as-rent change: - The rule predates 2011. ARM 42.4.302(5), in force from 8/20/2004 (Wayback captures of mtrules.org, 2008 and 2010), read "Property taxes billed are allowable as rent if the property occupied by an eligible claimant is in a name other than the claimant"; the 2017 restructuring made it (2)(b). The property_tax_in_another_name_as_rent parameter, false for 2009-2010, is removed, and the 2010/2011 cases become one 2009 case. - A home co-owned by the claimant and a dependent stays on line 23 with both bills, as before; only a home wholly in others' names, a dependent's included, moves to line 24 as rent. - State the actual basis for max(rent paid, bill): the rule's "may use" is a choice between two measures of one home's cost, and ARM 42.4.302(3)(a) and (3)(c)(v) count one housing cost or another "but not both". - New cases: a joint couple billed nothing counts the other member's bill once (kills a head-or-spouse double count that only Hypothesis caught), and a home co-owned with a dependent. - Cite the line 23 instructions from PDF p. 46; describe the bill-as-rent path as the model's treatment in comments and the test docstring. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

#9900 (with #9882 and #9877) has landed on main. Conflicts were add/add in the files #9900 created; each takes main's version with this PR's own diff (da7c17e..3d487c5) applied on top. This PR's five cases are appended after main's in the credit YAML. The stack's three changelog fragments are dropped, since main already compiled them. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

…s tax units Sol review r2 (finding 1): real_estate_taxes records an expense, not title, so a bill on a tax unit dependent cannot show a home wholly in the dependent's name. The microdata put a household's bill mostly on its reference person, who can be a dependent: in the 2024 run, one Montana tax unit (an 85-year-old head with the 68-year-old reference person as a dependent) lost its $646 credit, -$1.35M weighted, under the old rule. - Line 23 is again the tax unit's real_estate_taxes, dependents included, as on main (now an `adds`). ARM 42.4.302(2)(b) applies when no one in the tax unit is billed, through the household's bill on line 24. - Pin `ssi: 0` and give each person a marital unit in this PR's end-to-end and pre-limit cases; without marital units the elderly siblings formed a default SSI couple (finding 2). - Add a case with rent paid by a dependent and no bills: line 24 = 6,000, credit 900 (finding 4). - Qualify invariants 6 and 7 as holding with household income fixed (finding 3), and soften the max-over-sum comment, naming the bill-only-without-rent alternative. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Sol review r3 (nonblocking): a parent in the home of a child's joint return billed through the spouse counts the household's whole bill as rent (line 24 = 4,000, credit 600), which a head-only household sum would miss; and line 23 sums fractional bills exactly. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

MaxGhenis · 2026-10-18T18:37:02Z

Hand-off to the US + core hub (owner session local_cfad68c8-c3e7-430a-a77d-d14b93bfd5a0).

Head: c03d028f6e. The model code is unchanged since 88a93c5652; the last commit adds tests only.
Independent review: GPT-6.1 Sol, through Subfleet:
- r2 at a93de09280: REQUEST_CHANGES, one major and three minor findings, all fixed in 88a93c5652.
- r3 at 88a93c5652: APPROVE. Its two non-blocking test suggestions are implemented in c03d028f6e.
- r4 at c03d028f6e: APPROVE; its minor wording fixes are applied to the description.
Reports are review-sol-r2.md, review-sol-r3.md and review-sol-r4.md in ~/reviews/mt-ehrc-property-in-others-name-2026-10-06/.
Passed locally, one file at a time on the merged tree:
- all 13 MT elderly-credit YAML files;
- test_mt_elderly_credit_one_claimant.py (5) and test_mt_elderly_credit_household_members.py (3), with Hypothesis;
- test_reference_urls and test_no_concatenated_reference_urls.
Pending: CI on c03d028f6e, and a non-draft review approval for merge.
Impact: none in 2024 or 2026: main 5ec60b209a against 88a93c5652, full population, through hub lockrun.sh. Details are in the body and impact/.
Depends on: nothing open. Limit the Montana elderly homeowner/renter credit to one claimant per household (MCA 15-30-2341(1)) #9900, Count household members' income in Montana's elderly homeowner/renter credit #9882 and Align Montana separate-filing deductions and the elderly credit's income with the forms #9877 have merged, and main is merged in.
Decision: d1035, the homestead reading, is open and is not a hold. This PR implements its default, the form reading. d1035's note records what a homestead ruling would change here, and the max-versus-bill-only-without-rent alternative. Max's original request delegated the line 24/25 choice.
Axiom: rulespec-us#1512 queued; the extension comment is posted and was revised on 2026-10-18.
Follow-ups owed: none from this session.

MaxGhenis · 2026-10-18T20:22:16Z

US + core hub merge audit, us#9945 at c03d028f6ef983ebdb8a4179f284e8febd566007 (squash): Count property tax billed in another household member's name as rent in Montana's elderly homeowner/renter credit (ARM 42.4.302(2)(b)).

Review: GPT-6.1 Sol via Subfleet. r3 APPROVED 88a93c5 after executing the tests: 49 end-to-end YAML, 13 gross-rent YAML and 5 Python cases, including both Hypothesis tests. r4 APPROVED this exact head c03d028. Its delta from r3 is test-only (three YAML files, +92 lines; model code unchanged), and CI executes those cases. Reports: ~/reviews/mt-ehrc-property-in-others-name-2026-10-06/review-sol-r{2,3,4}.md.
Gates checked live at merge:
- gh pr checks exits 0;
- the latest Pull request run at the head concluded success;
- MERGEABLE;
- not a draft;
- no reviewer's latest review requests changes;
- the semantic-overlap guard;
- head pinned.
Impact: Hub lockrun full-population run, main 5ec60b2 against 88a93c5 (the model code at this head), 2024 and 2026: no change beyond rounding (weighted +$0.38 in 2024, +$0.22 in 2026), detailed in the description.
Order: Montana homestead reading d1035 RULED by Max on 2026-10-12: keep the form reading, which this PR implements. No open dependency; Limit the Montana elderly homeowner/renter credit to one claimant per household (MCA 15-30-2341(1)) #9900, Count household members' income in Montana's elderly homeowner/renter credit #9882 and Align Montana separate-filing deductions and the elderly credit's income with the forms #9877 are merged.
Axiom: Encode Montana separate-filing deductions through 2023 and elderly homeowner/renter credit income without losses TheAxiomFoundation/rulespec-us#1512 queued (ARM 42.4.302(2)(b) evidence, review_finding addendum and companion cases in this comment; signed-encoder runs need approval and ARM 42.4.302 and the Montana forms are not in the pinned corpus)

MaxGhenis and others added 15 commits October 6, 2026 07:08

Attribute Schedule 2EC quotes to the form's line labels, not the inst…

11b47a5

…ructions Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Preserve dependent AGI adjustments for Montana elderly credit

10c7727

Merge main to retain Montana mortgage-interest fixes

936cbce

Apply Montana elderly credit multiplier to negative household income

5b965e1

Supply explicit filer roles in Montana income property tests

261e65b

MaxGhenis force-pushed the fix-mt-ehrc-property-in-others-name branch from d6a512b to b209688 Compare October 11, 2026 16:03

MaxGhenis and others added 3 commits October 18, 2026 12:45

MaxGhenis marked this pull request as ready for review October 18, 2026 18:17

MaxGhenis merged commit a110908 into main Oct 18, 2026
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MaxGhenis deleted the fix-mt-ehrc-property-in-others-name branch October 18, 2026 20:22

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Count property tax billed in another household member's name as rent in Montana's elderly homeowner/renter credit (ARM 42.4.302(2)(b)) - #9945

Count property tax billed in another household member's name as rent in Montana's elderly homeowner/renter credit (ARM 42.4.302(2)(b))#9945
MaxGhenis merged 19 commits into
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fix-mt-ehrc-property-in-others-name

MaxGhenis commented Oct 6, 2026 •

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MaxGhenis commented Oct 18, 2026

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MaxGhenis commented Oct 18, 2026

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MaxGhenis commented Oct 6, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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Summary

The homestead reading (decision d1035) is not implemented

How "as rent" enters Schedule 2EC

Example: 2024, a parent living in an adult child's home

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MaxGhenis commented Oct 18, 2026

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MaxGhenis commented Oct 18, 2026

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MaxGhenis commented Oct 6, 2026 •

edited

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