You own your house and live in it. Can you share one or two spare rooms with people who are not family, for a month or longer? This page answers that question for Montana, from its state laws and a sample of its cities and counties. We call it a typical home share.

Montanaat a glance

Montana law

Should you worryabout zoning?

Answer four quick questions. We will show you what the rules we found say for a home like yours, and what to ask your city or county. It works for homeowners and for the family members helping them.

Check your situation

Cities and countiesin Montana

Cities and counties

Details for each location

This page is here to help you learn and to give you context. It does not interpret any zoning code and is not legal advice. Rules vary and change, and only your city or county planning office can say what applies to your home.

What the law asksof a home share

Where a state's landlord and tenant law covers home sharing, it gives you and your home sharer a few ground rules. Knowing them up front makes for a better agreement and fewer surprises.

Ground rules in Montana

Sharing, boarding, renting, rooming:what the words mean

The laws and codes rarely say "home sharing." They use older words, and each city or county can define them differently. Here is what each word means in everyday terms, and how Montana and the locations in our sample use it.

For local leaders

For the national picture, the history of these rules, and more resources, see The Rules Behind the Spare Room.

This page is here to help you learn and to give you context. It does not interpret any zoning code and is not legal advice. Rules vary and change, and only your city or county planning office can say what applies to your home.

Citations, Definitions & SourcesOpen the fine printClose the fine printEvery rule on this page is quoted from a law, a code, or a court opinion, with the date we checked it. The sources for Montana are available by clicking Open the Fine Print.

Definitions

A typical home share. You own your house and live in it, and you share one or two spare rooms with people who are not family, for a month or longer.

The six answers. Yes: the rules we found allow a typical home share with no extra step. Yes, with limits: they allow it but set a limit, such as a number of people or rooms. Yes, after a permit or sign-up: they allow it once a step is done. Not clear: the rules do not answer it either way, or we could not read them. No county zoning found: the county and state sources we read show no county zoning code, though none says so in words. No: the rules do not allow it.

State policy and zoning toward home sharing. The map groups states by what their laws and plans do for home sharing today. A state is Leading when two things are true. First, its law stops cities and counties from limiting who lives together based on family ties, in all cases or in some. Second, the state has committed to home sharing: it names home sharing in its State Plan on Aging, an aging strategy, or an affordable housing plan, funds an ongoing home sharing program, or has a law that allows such funding. A one-time pilot is a welcome first step, but it does not count as a statewide commitment. A state is Supportive when one of the two is true, Open when neither is but its landlord and tenant law clearly covers home sharing, and Getting started when none of these is true yet. A state is marked as an opportunity, in a lighter shade on the map, when it has committed to home sharing but its laws do not yet protect home sharing statewide or do not yet say clearly which ground rules apply. Every check traces to a cited source on the state's page. The groups describe state law and policy, not how welcoming any community is, and not what any particular home may do.

Single housekeeping unit. Many zoning codes say a family or household must live as a "single housekeeping unit." The phrase describes people who live together as one household, sharing the home, rather than as separate tenants under one roof. Most codes use it without saying more, and each city or county decides what it means. The codes in our sample that spell it out point to the same kinds of things: sharing the kitchen and living areas, sharing chores and expenses, and, as signs of separate households, locks on bedroom doors or separate leases. Where a city or county on this page defines the phrase, its entry quotes the definition under Read the code. If your city or county's code uses the phrase, ask the planning office how it applies to a home share, such as one where the person sharing your home pays rent and has their own room.

Checked. The date we last read the source itself. Codes change. Your planning office has the current version.

Sources for Montana

SourceWhere it is used
MCA 70-24-104 (2025) [En. Sec. 8, Ch. 313, L. 1977; amd. Sec. 1, Ch. 282, L. 2003]Montana. Checked 2026-10-08. Open the source.
MCA 70-24-103 (2025) [last amd. Sec. 1, Ch. 768, L. 2025]Montana. Checked 2026-10-08. Open the source.
Montanans Against Irresponsible Densification, LLC v. State of Montana, 2024 MT 200, No. DA 24-0039 (decided 3 September 2024)Montana. Checked 2026-10-08. Open the source.
Montanans Against Irresponsible Densification, LLC v. State of Montana, 2026 MT 53, No. DA 25-0200 (decided 17 March 2026)Montana. Checked 2026-10-08. Open the source.
Village of Belle Terre v. Boraas, 416 U.S. 1 (1974)Montana. Checked 2026-10-08. Open the source.
Moore v. City of East Cleveland, 431 U.S. 494 (1977)Montana. Checked 2026-10-08. Open the source.
MCA 76-2-345 (2025)Montana. Checked 2026-10-08. Open the source.
MCA 76-2-215 (2025)Montana. Checked 2026-10-08. Open the source.
MCA 76-2-304 (2025)Montana. Checked 2026-10-08. Open the source.
MCA 70-24-441 (2025)Montana. Checked 2026-10-08. Open the source.
MCA 70-25-202 (2025) [last amd. Sec. 2, Ch. 656, L. 2025]Montana. Checked 2026-10-08. Open the source.
MCA 70-24-303 (2025)Montana. Checked 2026-10-08. Open the source.
MCA 70-24-321 (2025)Montana. Checked 2026-10-08. Open the source.
MCA 70-24-411 (2025)Montana. Checked 2026-10-08. Open the source.
MCA 49-2-305 (2025) [last amd. Sec. 3, Ch. 205, L. 2011]Montana. Checked 2026-10-08. Open the source.
42 U.S.C. 3603(b)(2)Montana. Checked 2026-10-08. Open the source.
42 U.S.C. 1982Montana. Checked 2026-10-08. Open the source.
Jones v. Alfred H. Mayer Co., 392 U.S. 409 (1968): section 1982 "contains none of the exemptions" in the Fair Housing ActMontana. Checked 2026-10-08. Open the source.
Fair Housing Council v. Roommate.com, LLC, 666 F.3d 1216 (9th Cir. 2012): "we interpret the FHA and FEHA as not applying to the sharing of living units"Montana. Checked 2026-10-08. Open the source.
Montana State Plan on Aging FFY 2024-2027 (2024 amendment)Montana. Checked 2026-10-08. Open the source.
Governor's Housing Task Force Phase I report, 2022Montana. Checked 2026-10-08. Open the source.
Governor's Housing Task Force Phase III report, 2024Montana. Checked 2026-10-08. Open the source.
Billings City Code 27-1803, DefinitionsBillings, Montana. Checked 2026-10-09. Open the source.
Billings City Code 27-1001, General provisions (use categories)Billings, Montana. Checked 2026-10-08. Open the source.
Billings City Code 27-1002, Uses by districtBillings, Montana. Checked 2026-10-09. Open the source.
Billings City Code 7-601, Definitions (rooming house)Billings, Montana. Checked 2026-10-08. Open the source.
Billings City Code 7-603, State license and city business tax requirementsBillings, Montana. Checked 2026-10-08. Open the source.
Billings City Code 27-1621, Short-term rental permitsBillings, Montana. Checked 2026-10-08. Open the source.
Helena City Code 11-2-4, Land Use Definitions for Zoning Districts (2026 S-11, current through Ord. 3330)Helena, Montana. Checked 2026-10-08. Open the source.
Helena City Code 11-2-3, Land Use Table for Zoning Districts, Table 1Helena, Montana. Checked 2026-10-08. Open the source.
Helena City Code 11-1-2, Definitions (Title 11)Helena, Montana. Checked 2026-10-08. Open the source.
Helena City Code 1-1-5, DefinitionsHelena, Montana. Checked 2026-10-08. Open the source.
Helena City Code 4-1-1, Business Licenses, Definitions ("Commercial Enterprise")Helena, Montana. Checked 2026-10-08. Open the source.
MCA 15-68-101, Definitions (short-term rental)Helena, Montana. Checked 2026-10-08. Open the source.

Cite This Paper

HomeShare Oregon. (2026). The Rules Behind the Spare Room: Montana. https://homeshareoregon.org/research/rules-behind-the-spare-room/montana/

About HomeShare Oregon

HomeShare Oregon publishes this paper as students of aging, housing, and community infrastructure. We operate one of many possible interventions in the missing middle. We believe the most useful contribution we can make to the larger field is to add a frame and a research agenda, rather than to argue for our particular role within it.

If you are working on related questions, we would like to hear from you. Email the executive director at executivedirector@homeshareoregon.org.