Montana

Montana's HOA statute Mont. Code Ann. § 70-17-901 (https://mca.legmt.gov/bills/mca/title_0700/chapter_0170/part_0090/section_0010/0700-0170-0090-0010.html) prohibits an HOA from adopting or enforcing a covenant amendment that imposes more onerous use restrictions than those in place when a member acquired their interest, unless the affected member consents in writing. After 2019-05-09, an HOA also may not enforce a covenant in a way that limits uses that were allowed when the member acquired the property. This is a one-way ratchet protecting existing uses, not an affirmative ADU preemption: an HOA's pre-existing covenant prohibiting ADUs remains enforceable against owners who took title with that restriction in place. SB 528's text expressly addresses municipal zoning, not private covenants, and § 70-17-901(2) carves out covenants required to comply with applicable federal, state, and local laws — but a covenant banning ADUs is not 'required' by SB 528, so the carve-out does not flip pre-existing ADU bans. A homeowner subject to an HOA covenant prohibiting ADUs has no state-law remedy under current Montana law and must seek the consent or amendment process within the association.

Montana Board of Housing (MBOH) under the Montana Department of Commerce does not operate an ADU-specific loan or grant product as of 2026-04-26. Construction or rehab of an ADU on a primary residence may be financed indirectly through MBOH's Regular Bond Loan Program (30-year, low-interest first mortgage geared to first-time buyers under income and purchase-price limits) or the Bond Advantage / MBOH Plus Down Payment Assistance Programs (up to 5% / $15,000 in DPA). All MBOH first-mortgage products require qualifying for an underlying FHA, VA, RD, or HUD-184 loan; an existing ADU on the property is generally permissible. The Department of Commerce's Coal Trust Multifamily Loan Program funds rental housing developments which can include ADU-style units in multi-unit projects but is not a homeowner-facing instrument.

• Montana Board of Housing Regular Bond Loan Program
• Bond Advantage Down Payment Assistance Program
• MBOH Plus 0% Deferred Down Payment Assistance Program

Montana does NOT operate a FAIR Plan or any state residual property-insurance market as of 2026-04-26. Property-insurance regulation falls under the Montana Commissioner of Securities and Insurance (CSI). Wildfire risk is acute (Montana ranks #2 nationally for share of homes at catastrophic-wildfire risk; ~70% of recorded fires have occurred since 2000), and admitted carriers have non-renewed or declined coverage in many WUI areas around Bozeman, Missoula, the Bitterroot, and the Flathead. A December 2025 University-led report recommended a 'layered, adaptive' approach including a possible state FAIR plan, voluntary certification, parametric policies, and regulatory reform; no FAIR plan has been enacted. House Bill 533 (2025) requires insurers using wildfire-risk scores to disclose the underlying data and methodology on request — a transparency measure, not residual-market relief. Montana law currently prohibits local governments from mandating wildfire-mitigation building practices unless the practice is on a state-approved list. ADUs in WUI Montana inherit the primary dwelling's wildfire underwriting, often through surplus-lines markets or excess-and-surplus carriers when admitted carriers decline.

Montana does not operate a statewide pre-approved ADU plan catalog as of 2026-04-26. The 2023 Montana Miracle reform package (SB 528, SB 323, SB 245, SB 382) established the country's most aggressive state preemption of single-family-only zoning, but did not pair the preemption with a state plan library, impact-fee waiver fund, or per-ADU rebate. SB 382 (the Montana Land Use Planning Act, https://archive.legmt.gov/bills/2023/BillPdf/SB0382.pdf) restructures comprehensive-planning requirements for cities of 5,000+ residents toward a more streamlined, plan-then-permit model. Implementation by the Department of Commerce and the Department of Environmental Quality continues; the DEQ Energy Code office published an ADU best-practices guide in fall 2023.

• Montana Land Use Planning Act (SB 382, 2023)
• DEQ Energy Code ADU Best Practices Guide (Fall 2023)