Montana — Personal Income Tax

Montana requires an individual income tax return if you were a Montana resident, part-year resident, or nonresident with Montana source income during the tax year, and you were required to file a federal income tax return under the Internal Revenue Code. Even if you are not required to file a federal return, you must file a Montana return if you have Montana taxable income after applying the Montana-specific additions and subtractions to federal taxable income.

Certain nonresidents may qualify for a filing exclusion. Nonresidents who earned only wages for services performed in Montana for 30 days or fewer and who worked in more than one state during the tax year do not have to file or pay Montana tax on that income, unless they have other Montana source income. This exclusion does not apply to self-employed individuals.

Source: Mont. Code Ann. § 15-30-2602 | Montana DOR, Individual Filing Requirements

For tax years beginning January 1, 2026, Montana imposes a two-bracket graduated tax on ordinary income (taxable income other than net long-term capital gains) at the following rates: 4.7% on Montana taxable income up to $95,000 for married filing jointly and qualifying surviving spouses, up to $71,250 for heads of household, and up to $47,500 for single filers, married filing separately, estates, and trusts. Income above those thresholds is taxed at 5.65%.

2027 bracket and rate expansion: Under House Bill 337 (2023), the bracket thresholds expand further for tax years beginning January 1, 2027, and the top rate is reduced to 5.4%. For tax year 2027:

• Married filing jointly and surviving spouses: 4.7% on taxable income up to $130,000; 5.4% on income over $130,000
• Heads of household: 4.7% up to $97,500; 5.4% over $97,500
• Single, married separately, estates, and trusts: 4.7% up to $65,000; 5.4% over $65,000

These thresholds and rates remain in effect unless further legislation is enacted.

Scheduled statutory sunset (end of TY 2028): All temporary provisions—including the expanded brackets and reduced rates introduced by HB 337—are scheduled to sunset at the end of tax year 2028. Unless renewed or amended, the prior law would then apply beginning in tax year 2029. The sunset is confirmed by the Montana Legislative Fiscal Division. For planning purposes, practitioners should watch for legislative updates and Department of Revenue notices as 2028 approaches to determine the applicable rate and bracket regime for tax years after 2028.

Summary Table: | Tax year | Filing Status | Lower Bracket/Rate | Upper Bracket/Rate | |----------|--------------------|--------------------|-------------------| | 2026 | MFJ/Surviving Spouse | $0–$95,000 @ 4.7% | Over $95,000 @ 5.65% | | 2026 | Head of Household | $0–$71,250 @ 4.7% | Over $71,250 @ 5.65% | | 2026 | Single/MFS/Estate/Trust | $0–$47,500 @ 4.7% | Over $47,500 @ 5.65% | | 2027+ | MFJ/Surviving Spouse | $0–$130,000 @ 4.7% | Over $130,000 @ 5.4% | | 2027+ | Head of Household | $0–$97,500 @ 4.7% | Over $97,500 @ 5.4% | | 2027+ | Single/MFS/Estate/Trust | $0–$65,000 @ 4.7% | Over $65,000 @ 5.4% |

Source: Mont. Code Ann. § 15-30-2103 (Temporary) Source: Montana Legislative Fiscal Division, History of Montana Individual Income Tax Changes, Feb. 2026 Source: Montana DOR, HB 337: 2026–2027 Individual Income Tax Changes

For tax year 2026, Montana taxes net long-term capital gains separately from ordinary income at preferential rates of 3.0% and 4.1%. For married filing jointly and qualifying surviving spouses, the rate is 3.0% on the first $95,000 less nonqualified taxable income of net long-term capital gains, and 4.1% on amounts exceeding that threshold. If nonqualified taxable income (ordinary income) is $95,000 or greater, all net long-term capital gains are taxed at 4.1%. For heads of household, the 3.0% rate applies to the first $71,250 less nonqualified taxable income; for single filers, married filing separately, estates, and trusts, the threshold is $47,500 less nonqualified taxable income. Net long-term capital gains are defined by reference to IRC § 1222.

Source: Mont. Code Ann. § 15-30-2103 | Montana DOR, HB337: 2026–2027 Individual Income Tax Changes

Montana determines taxable income by starting with federal taxable income and applying Montana-specific additions and subtractions. Montana does not have a separate state standard deduction; the federal standard deduction is already reflected in federal taxable income before Montana's calculation begins. This method has been in effect since tax year 2024, when Montana repealed its prior 20%-of-AGI state standard deduction and eliminated itemized deduction provisions that previously existed under former Mont. Code Ann. § 15-30-2131 and § 15-30-2132.

Source: Mont. Code Ann. § 15-30-2120

Montana classifies individuals for income tax purposes as residents, part-year residents, or nonresidents. The classification determines the scope of income subject to Montana tax: residents are taxed on all income regardless of source; part-year residents are taxed on all income received while a Montana resident plus Montana-source income received while a nonresident; nonresidents are taxed only on Montana-source income.

Resident. Mont. Code Ann. § 15-30-2101(31) defines "resident" as any natural person who is (1) domiciled in Montana, or (2) maintains a permanent place of abode within Montana even though temporarily absent from the state and who has not established a residence elsewhere. Either prong suffices for resident status.

"Domiciled" means having a residence in Montana as stated in Mont. Code Ann. § 1-1-215, which defines domicile as the place where an individual has a true, fixed, principal, and permanent home and to which the individual intends to return whenever absent. "Permanent place of abode" is defined in Mont. Admin. r. 42.15.107(2) as "a dwelling place habitually used by an individual as the individual's home, whether or not owned by the individual or a dwelling the individual may someday leave."

Mont. Admin. r. 42.15.109(1) provides that whether an individual is a Montana resident "is determined in light of all facts and circumstances." The Montana Department of Revenue states that if an individual maintains a place of abode in both Montana and another state, and both show similar permanency characteristics, the department may look at "whether the individual has abandoned residency in one state in favor of another state through affirmative actions." The DOR cites as examples of factors indicating Montana residency: Montana voter registration, Montana resident hunting and fishing licenses, and a Montana driver's license.

Part-year resident. The Montana DOR defines a part-year resident as an individual who either (1) was a Montana resident at the start of the year and then established residency in another state during the year, or (2) was a nonresident at the start of the year and then established residency in Montana during the year. This requires an actual change of residency status with the intention of establishing a permanent residence in the new state.

The DOR clarifies that the following individuals are not part-year residents: (a) retirees (commonly called "snowbirds") who are residents of Montana but live in another state for a portion of each year; (b) a resident of another state who works in Montana on a seasonal basis but does not establish residency in Montana; and (c) a Montana resident attending an out-of-state college who has not established residency elsewhere.

Nonresident. Mont. Code Ann. § 15-30-2101(23) defines a "nonresident" as a natural person who is not a resident. A nonresident is taxed only on Montana-source income. Section 15-30-2101(21) defines Montana-source income to include, among other items, wages for services performed in Montana, income from property located in Montana, and income from a business conducted in Montana.

Special rules for military personnel. Mont. Admin. r. 42.15.109(2) provides that a Montana resident who enters the U.S. armed forces does not lose Montana resident status solely by reason of being absent from the state in compliance with military orders. Conversely, Mont. Admin. r. 42.15.112(1) provides that a nonresident member of the armed forces who is living in Montana solely by reason of compliance with military orders does not become a Montana resident solely by being present in the state, and their compensation for military service is not Montana-source income. The DOR guidance explains that under the federal Military Spouses Residency Relief Act, starting in 2009, some nonresident spouses who move to Montana solely to be with a nonresident serviceperson are also allowed to retain their home residence or domicile and, subject to certain rules and limitations, their wage and other personal services income is not Montana-source income.

Source: Mont. Code Ann. § 15-30-2101 | Mont. Admin. r. 42.15.109 | Mont. Admin. r. 42.15.107 | Mont. Admin. r. 42.15.112 | Montana DOR, Residency

Montana individual income tax returns are due on or before April 15 following the close of the calendar year. For fiscal-year filers, the return must be filed on or before the 15th day of the 4th month following the close of the taxpayer's fiscal year. This deadline is established by Mont. Code Ann. § 15-30-2604(1)(a).

Holiday deferral. If the April 15 due date falls on a holiday that defers a filing date as recognized by the Internal Revenue Service but that is not observed in Montana, the return may be made on the first business day after the holiday. Mont. Code Ann. § 15-30-2604(1)(b)(i).

Automatic six-month extension. Montana grants an automatic extension of time for filing of up to six months following the prescribed due date. Mont. Code Ann. § 15-30-2604(3)(a). For calendar-year filers, this moves the extended deadline to October 15. Montana does not require taxpayers to file a separate extension form or request — the extension is automatic.

Extension is for filing only, not payment. The extension of time for filing a return is not an extension of time for payment of taxes. Mont. Code Ann. § 15-30-2604(5). All tax due must be paid by the original April 15 deadline (or the applicable fiscal-year deadline). Any tax not paid by the original deadline is subject to penalty and interest as provided in Mont. Code Ann. § 15-1-216. Mont. Code Ann. § 15-30-2604(3)(b).

Disaster relief. The Montana Department of Revenue may extend filing dates and defer or waive interest, penalties, and other late-filing consequences for a period not exceeding one year for taxpayers affected by a federally declared disaster or a terroristic or military action recognized for federal tax purposes under 26 U.S.C. § 7508A. Mont. Code Ann. § 15-30-2604(1)(b)(ii). Additionally, the department may grant an additional extension of time for filing a return whenever in its judgment good cause exists. Mont. Code Ann. § 15-30-2604(4).

Source: Mont. Code Ann. § 15-30-2604

For tax years beginning January 1, 2027, the Montana top individual ordinary income tax rate is 5.4%, as set by HB 337 (2023) and codified in Mont. Code Ann. § 15-30-2103. The 5.4% top rate applies to income above the statutory bracket thresholds (e.g., $130,000 for married filing jointly), replacing the 5.65% top rate that was in effect in tax year 2026.

Statutory step-down triggers for additional reductions: Beginning in tax year 2028 and later, the law authorizes a possible further reduction of the top rate if Montana's budget stabilization/reserve triggers are met (see § 15-30-2103(1)(a)(ii)(B)–(D)). However, as of July 1, 2026, the Montana Department of Revenue (DOR) has not issued any annual guidance or notice confirming a reduced top bracket rate below 5.4% for tax year 2027 or for projection years beyond 2027. The DOR's most recent official news release, "HB 337: 2026–2027 Montana Individual Income Tax Changes," confirms the 5.4% top rate for 2027 and notes that any further reductions would require the statutory triggers to be met, with confirmation announced by the Department if and when those conditions occur.

How practitioners confirm the applicable rate each year: Practitioners should confirm the ordinary income top bracket rate each year by consulting these primary sources:

• The current Montana Code Annotated at § 15-30-2103
• Any news releases or notices published by the Montana DOR in the "Recent News" and "Notices" sections of the Department's website
• The Department's Form 2 Individual Income Tax return instructions for the relevant filing year (often summarizes the current top rates within the "Tax Rate Schedules" section)
• If the step-down trigger is met for a future year, the Department is expected to issue a formal announcement, which should be published in advance of the applicable tax year in both written notices and the "Tax Rates"/"What's New" section of the DOR site.

As of July 1, 2026, there are no DOR-issued notices adjusting the top ordinary individual income rate below 5.4% for 2027 or later. Historical and current rate announcements as well as future trigger notifications are maintained on the Montana DOR website and should be reviewed annually by practitioners.

Source: Montana DOR, HB 337: 2026–2027 Montana Individual Income Tax Changes Source: Mont. Code Ann. § 15-30-2103

Not yet human confirmed. This reflects a review of all available DOR notices through July 1, 2026. Practitioners should check the official DOR news and notices each year for any updated trigger or rate announcements.

Effective January 1, 2027, Montana’s net long-term capital gains are taxed under a two-rate, bracketed system as revised by HB 337 (2023). The rates are 3.0% and 4.1%, with the thresholds aligned to the new ordinary income brackets for tax year 2027 and future years.

Bracket structure for net long-term capital gains (2027 and later):

• Married filing jointly & surviving spouse:
• 3.0% on the portion of net long-term capital gains that, when combined with ordinary taxable income, does not exceed $130,000 (i.e., ordinary income fills the floor of the bracket first; only capital gains in any remaining threshold are taxed at 3.0%).
• 4.1% on any additional net long-term capital gains exceeding $130,000 combined threshold — or all capital gains if ordinary income alone reaches $130,000 or more.
• Head of household:
• 3.0% up to $97,500, minus ordinary taxable income in that bracket.
• 4.1% above $97,500.
• Single, married filing separately, estates, and trusts:
• 3.0% up to $65,000, minus ordinary taxable income.
• 4.1% above $65,000.

In practical terms, only the portion of long-term capital gains below the threshold—after accounting for ordinary income—is taxed at 3.0%. If ordinary taxable income meets or exceeds the filing status threshold, all long-term capital gains are taxed at 4.1%.

Annual inflation adjustment. Thresholds are subject to annual adjustment using the Consumer Price Index for All Urban Consumers (CPI-U) as specified in statute. For tax years after 2027, refer to Department of Revenue notices for indexed amounts.

Definitions. Net long-term capital gains follow the federal definition (IRC § 1222). Ordinary income refers to “nonqualified taxable income” under Montana law.

Source: Mont. Code Ann. § 15-30-2103 | Montana DOR, HB 337: 2026–2027 Montana Individual Income Tax Changes

For tax years 2025 and 2026, Montana continues to require additions to federal taxable income using the categories set out in Mont. Code Ann. § 15-30-2120(2). These include:

• Interest income from obligations of any state, territory, or political subdivision other than Montana and its subdivisions (if not included in federal taxable income);
• Refunds of federal income tax and recoveries that provided a Montana tax benefit in prior years (to the extent not already included in federal taxable income);
• Expenses deducted in computing federal taxable income that are tied to certain federal credits (if the credit is claimed on the federal return and the expense was also deducted for federal purposes),
• Net operating loss deductions claimed for federal purposes;
• Any other addition required by Montana rule.

As of July 1, 2026, a review of the Montana Code Annotated, all rulemakings under Title 42, Chapter 15 published in the Montana Administrative Register covering calendar years 2024 to mid-2026, and currently available Montana Department of Revenue guidance confirms there have been no new Montana-specific additions adopted for tax year 2025 or 2026. There have been no administrative rules, DOR bulletins, or supplemental add-backs required by rule or guidance for those years. Only periodic inflation adjustments to certain subtraction caps have occurred.

Taxpayers and practitioners should consult annually updated Department instructions and the latest published statutes, but as of July 1, 2026, the Montana additions required are those listed in Mont. Code Ann. § 15-30-2120(2) and rules in effect prior to 2025.

Source: Mont. Code Ann. § 15-30-2120

Not yet human confirmed. This reflects a July 1, 2026, review of the latest available statutory, regulatory, and DOR sources.

Montana law requires specific subtractions from federal taxable income to determine Montana taxable income. These are enumerated in Mont. Code Ann. § 15-30-2120(3) and must be applied after any Montana additions. Each subtraction below tracks the statute closely. Practitioners should reference the current text and Montana Form 2 Instructions each year for amendments or new eligible categories.

Key retirement income subtractions and limitations (for tax year 2025 and later):

(1) Age-65 or older subtraction. For taxpayers age 65 or older, Montana allows a subtraction—$5,660 for tax year 2025 ($11,320 if both spouses qualify and file jointly)—subject to annual inflation indexing. However, this subtraction is phased out as federal adjusted gross income increases: the allowable amount is reduced by $1 for every $1 by which federal AGI exceeds set thresholds. The phaseout thresholds and the subtraction amounts are published annually in the Montana Form 2 Instructions. Higher income taxpayers may receive only a partial subtraction—or none.

(2) Working military retirement subtraction. Working military retirees (and certain survivor beneficiaries) may subtract the lesser of (a) 50% of military retirement or survivor benefits, or (b) total Montana-source earned income, for up to five consecutive years. The subtraction applies only if the taxpayer has Montana-source earned income in the tax year claimed. Detailed rules and definitions are provided in Mont. Admin. R. 42.15.1510 and in the DOR's Form WMRE instructions. Claimants must attach Form WMRE each year.

(3) Railroad Retirement subtractions. Tier I and Tier II Railroad Retirement benefits, to the extent included in federal taxable income, may be fully subtracted. Most Railroad Retirement benefits are not federally taxable, so the Montana subtraction applies only to those amounts still included in federal taxable income (report on Schedule I, lines 22 and 23, Form 2).

Other statutory subtractions (see statute and prior content):

• Interest income from obligations of the U.S. government or of Montana to the extent included in federal taxable income but exempt for Montana purposes;
• Refunds of Montana income tax included in federal taxable income;
• Workers’ compensation, unemployment compensation, public assistance program benefits, or Social Security benefits, to the extent included in federal taxable income;
• Active-duty military or hazardous duty pay, to the extent included in federal income and not otherwise excluded;
• Lump sum distributions from qualified retirement plans, as set forth in rule;
• Income exempt under other provisions of Montana law;
• Any other subtraction as may be required by rule under Title 15, chapter 30, part 26.

Practitioner guidance:

• The age-65 and military retiree subtractions are not universally available; both are subject to income limitations and narrow eligibility rules. The age-65 subtraction is phased out above set AGI levels, and the military retirement subtraction requires current-year Montana-source earned income. Always confirm annual amounts and phaseout formulas in the Montana Form 2 Instructions and attach Form WMRE for military claims. Most standard IRA/401(k) distributions are fully taxable in Montana unless the taxpayer qualifies for an above subtraction.

Source: Mont. Code Ann. § 15-30-2120 Source: Mont. Admin. R. 42.15.1510 Source: Montana Department of Revenue, 2025 Montana Individual Income Tax Return (Form 2) Instructions

Not yet human confirmed. This update integrates statutory command, regulation, and Form 2/DOR instructional detail as of July 2026. Reviewers should check the current year's DOR instructions for threshold changes and eligibility nuances.

Montana provides a state earned income tax credit (EITC) determined as a direct percentage of the federal earned income tax credit (EITC) claimed by a taxpayer for the same tax year.

Credit Rate and Effective Dates:

• For tax years 2024 and 2025, the Montana EITC is 10% of the federal earned income tax credit. This is established in Mont. Code Ann. § 15-30-2318 as last amended by the 2023 Legislature and confirmed in Department of Revenue publications for those years.
• Effective for tax year 2026 and after, the Montana EITC is 20% of the federal earned income tax credit, by statutory amendment (House Bill 337, 2025 Legislature). This is a material increase from prior years. For example: a taxpayer eligible for a $2,000 federal EITC in 2026 would receive a $400 Montana EITC (20% of the federal amount).

Calculation and Linkage to Federal Program: The Montana EITC is calculated as a fixed percentage of the actual federal EITC allowed on the individual's federal return. All eligibility, phase-outs, earned income tests, and qualifying child definitions match those of the federal EITC. If the IRS makes an adjustment on the federal EITC, the Montana credit is automatically adjusted.

Eligibility Criteria:

• The taxpayer must be a Montana resident for any part of the year.
• The taxpayer must qualify for and claim the federal EITC on the federal tax return.
• Taxpayers using "married filing separately" generally are not eligible unless qualifying as "considered unmarried" under federal EITC rules. A person claimed as a dependent on another's return is not eligible.

Refundability: The Montana EITC is fully refundable. If the credit exceeds the individual's Montana liability, the excess is refunded.

Administrative Conformity: The Montana DOR conforms to federal EITC program definitions for eligibility and calculation unless state law provides otherwise. Any substantive change in Montana rate or eligibility must be enacted by statute.

Summary Table: | Tax Year(s) | Montana EITC Rate | |-------------|------------------| | 2024–2025 | 10% of federal EITC | | 2026+ | 20% of federal EITC |

Recent change: The increase from 10% to 20% applies for tax year 2026 and after, per HB 337 (2025 Legislature). This is a statutory change and not a routine inflation adjustment.

Source: Mont. Code Ann. § 15-30-2318 Source: Montana Department of Revenue, Montana Earned Income Tax Credit Source: Montana DOR, HB 337: 2026–2027 Individual Income Tax Changes

Not yet human confirmed. This update reflects the scheduled statutory rate increase effective for tax year 2026 and later.

Montana law provides a limited filing exclusion for certain nonresidents who work within the state for 30 days or fewer in a tax year. However, specific categories of nonresidents are statutorily excluded from this safe harbor and must file a Montana income tax return regardless of the number of days worked in the state or the nature of the services performed, if they have Montana source income.

Categories of nonresidents excluded from the 30-day exclusion under Mont. Code Ann. § 15-30-2106(2):

The individuals specifically excluded from the 30-day filing exclusion are:

• (a) Professional athletes performing services in Montana;
• (b) Public entertainers or persons performing services in connection with a public entertainment event in Montana, including as a participant, or as a member of a performing group;
• **(c) Persons providing services to, or on behalf of, either a professional sports team or a public entertainment event, including but not limited to coaches, managers, trainers, or support staff as specified in statute;
• (d) Any individual receiving aggregate Montana lottery winnings of $5,000 or more in a tax year;
• (e) Individuals performing services as a construction laborer on a construction project site in Montana;
• (f) Any nonresident who is a key employee as defined in IRC § 416(i)(1)(A)(i) and whose federal compensation exceeded $500,000 for the preceding calendar year.

Only the above categories, as set out in the statute, are expressly excluded from the 30-day filing exclusion. As a result, these individuals must file a Montana return and pay income tax on Montana-source income even if they were present in the state for 30 days or fewer during the year.

Source: Mont. Code Ann. § 15-30-2106(2)

Montana law provides relief from individual income tax filing requirements for nonresident owners of pass-through entities (PTEs) in two scenarios: inclusion on a composite return or payment of the Pass-Through Entity Tax (PTET) at the entity level. As of January 10, 2024, interpretive and procedural authority on this point was clarified in Montana Department of Revenue Publication 4, and the controlling statutes were updated as of 2023.

Composite returns: Under Mont. Code Ann. § 15-30-3312(5), a partnership or S corporation may elect to file a composite tax return reporting and paying tax on behalf of nonresident individual owners. A nonresident owner whose only Montana-source income is included on such a composite return is not required to file a separate Montana personal income tax return. Key qualifications—relief applies only if:

• The owner is a nonresident individual or a disregarded single-member LLC owned by a nonresident individual, and
• The owner has no other Montana-source income besides their share from the PTE included on the composite return.

PTET election (entity-level tax): Montana also allows partnerships and S corporations to make a PTET election and pay income tax at the entity level under Mont. Code Ann. § 15-30-3326. For tax years 2023 and after, both the statute and Montana DOR Publication 4 clarify that nonresident individual owners whose only Montana-source income is subject to the PTET are also not required to file a Montana individual return. This departs from the Department's prior silence or ambiguity on whether entity-level payment sufficed. The DOR now states affirmatively: "If the pass-through entity has paid the PTET on behalf of a nonresident owner whose only Montana source income is from the PTE, the nonresident owner is not required to file a Montana tax return."

Recent legislative and administrative guidance: A review of updated Montana law (Mont. Code Ann. § 15-30-3326, as amended) and Department authority (Publication 4, dated Jan. 10, 2024) confirm there is now explicit statutory and administrative support for relieving an eligible nonresident individual from personal filing.

Summary

• Inclusion in a composite return or PTET election relieves a nonresident of Montana individual filing (if all Montana income is so included and no other source triggers a filing requirement).
• These rules apply for tax years 2023 and after; practitioners should always confirm current DOR publications for any late amendments.

Source: Mont. Code Ann. § 15-30-3312 Source: Mont. Code Ann. § 15-30-3326 Source: Montana Department of Revenue, Montana Publication 4 – Pass-Through Entity Tax Guide (Jan. 10, 2024)

The previously cited DOR URLs on this topic are no longer available as of July 2026, but Department Publication 4 and statutory updates have superseded them.

Not yet human confirmed. This update reflects a July 1, 2026, review of Montana PTET/composite relief for nonresident owners and corrects prior authority in light of new DOR guidance and statutory amendment.

Montana requires taxpayers to adjust their federal taxable income by specific state-defined additions and subtractions to arrive at Montana taxable income. These adjustments are governed by Mont. Code Ann. § 15-30-2120 and apply for tax years beginning January 1, 2024, and after.

Statutory starting point:

• Montana taxable income begins with federal taxable income (as defined by IRC § 63). Practitioners must then apply state-specific adjustments before reaching the final Montana taxable income figure on Form 2.

Key categories of Montana additions (Mont. Code Ann. § 15-30-2120(2)):

• Interest on obligations of another state or its political subdivisions (not Montana), if not already included in federal income
• Certain federal income tax refunds, if previously deducted for Montana purposes
• Recoveries of expenses previously deducted for Montana tax if they resulted in a state tax benefit
• Expenses deducted on the federal return that are tied to certain federal tax credits (like the disabled access credit or work opportunity credit) if the credit is claimed
• Net operating loss deductions allowed federally (Montana does not currently allow a separate state NOL deduction)
• Any other addition required by rule of the DOR (as of June 2026, no new additions by rule)

Key categories of Montana subtractions (Mont. Code Ann. § 15-30-2120(3)):

• Interest income from U.S. government, Montana state, or Montana local bonds (if included federally but exempt in Montana)
• Refunds of Montana income tax that were included in federal income
• Workers’ compensation, public assistance, unemployment compensation, or Social Security income (to the extent included federally)
• Certain military active duty and hazardous duty pay
• Specified lump sum qualified retirement distributions (when reported federally but not otherwise taxable by Montana)
• Income exempted under other specific Montana statutes
• Other subtractions required by rule (none confirmed for 2024 or 2025 as of June 2026)

How to find and use the list:

• The definitive lists of additions and subtractions are always stated in Mont. Code Ann. § 15-30-2120 and periodically updated. For each tax year, practitioners should refer to the latest published version of the statute and DOR Form 2 instructions to confirm current adjustments.

Source: Mont. Code Ann. § 15-30-2120

Nonresidents of Montana must file a Montana individual income tax return if they have any Montana-source income, not limited to wages, unless an exclusion or composite return applies.

General rule: A nonresident individual is required to file a Montana return if they have Montana-source income and are required to file a federal return. Montana-source income is broadly defined and includes, but is not limited to:

• Distributive share of partnership or S corporation income from Montana activities (not covered by a valid composite return)
• Income or gains from rental or sale of real estate or tangible property located in Montana
• Pass-through entity (PTE) distributions attributable to Montana
• Business or trade income from Montana even if through a disregarded entity (Form DE—filed by nonresident owners of single-member LLCs or disregarded entities holding Montana business income)
• Fiduciary income (estate or trust)

Pass-through entities: If a nonresident's only Montana-source income is from a partnership or S corporation and the entity files a composite return on their behalf, the nonresident is not required to file their own return. However, if the nonresident has any other Montana-source income, or is not included on a composite return, they must file individually. The PTET (pass-through entity tax) does not, by itself, relieve filing responsibility—see the "filing-requirement-pte-election" section for more detail.

Form reference: The Montana Form 2 instructions require all Montana-source income to be reported by nonresidents, including partnership, S corporation, trust, rental, and capital gain income derived from sources in Montana. Gains from the sale or exchange of property located in Montana are specifically Montana-source and trigger a filing responsibility if federal requirements are met. Disregarded entities owned by nonresidents must file Form DE to attach income to the individual's Montana return.

Statutory and regulatory authority:

• Mont. Code Ann. § 15-30-2602 (individual filing requirement)
• Mont. Admin. R. 42.15.301(1)(b) (nonresident with Montana-source income)
• Montana DOR, Individual Filing Requirements
• Montana Form 2 Instructions (2024)
• Montana DOR, Form DE instructions

Source: Mont. Code Ann. § 15-30-2602 Source: Mont. Admin. R. 42.15.301 Source: Montana Department of Revenue, Filing Requirements Source: Montana Individual Income Tax Return (Form 2) Instructions 2024 Source: Montana Department of Revenue, Form DE Instructions

Not yet human confirmed. Practitioners should check annual instructions and DOR bulletins for year-to-year updates or additional exceptions.

Montana does not automatically conform to federal IRS extensions of tax deadlines granted for federally declared disasters, military service, or holidays. The state generally provides parallel relief only if (1) the Montana Department of Revenue (DOR) issues an announcement offering the same extension or (2) the taxpayer follows Montana-specific procedures to claim it. Relief requires positive taxpayer action and sometimes a separate state determination.

Federal disaster relief: When the IRS grants deadline extensions for federally declared disasters, the Montana DOR states it "provides the same filing, reporting, and payment extensions for income tax returns and payments as the IRS does." However, this relief is not automatic—taxpayers must indicate the type and date of disaster in bold red letters at the top of their return, or attach a letter with these details when filing electronically. The DOR site makes clear: "Taxpayers must claim this relief by making it visible on their return." Montana relief will match the federal time frame, but only upon proper identification and if Montana agrees to conform for the event.

Military and combat zone relief: Service members serving in a combat zone or contingency operation are eligible for Montana deadline extensions paralleling federal rules (usually 180 days after the qualifying period ends, and any additional federal IRS days), but the taxpayer must write "COMBAT ZONE or CONTINGENCY OPERATIONS EXTENSION" in red letters on the Montana tax return to claim the extension. Relief is not triggered automatically; annotation is necessary.

Holidays and due dates: Under Mont. Code Ann. § 15-30-2604, if the normal April 15 due date falls on a Saturday, Sunday, or a legal holiday recognized in Montana, the deadline moves to the next business day. Federal legal holidays that are not recognized by Montana do not by themselves move the Montana deadline, unless Montana DOR separately announces it.

Summary: Montana does not have automatic conformity to all IRS deadline relief. For both disaster and military relief, taxpayers must affirmatively claim the benefit by following DOR instructions. For holidays, only those observed by state law allow an automatic due date shift. Montana DOR may issue additional announcements for federal disaster events on a case-by-case basis.

Source: Montana DOR—Natural Disaster Relief Individual Income Tax Extension Source: Montana DOR—Filing on Extension (combat zone, military relief) Source: Mont. Code Ann. § 15-30-2604

Not yet human confirmed.