Yellowstone County, Montana Building Permit Guide

Since October 1, 2003 the City of Billings has not issued building, plumbing, mechanical or electrical permits outside the city limits; certain permits there come from the State of Montana Building Codes Division. Zoning, floodplain and septic steps stay local: the City/County Planning Division, the county Floodplain Office and RiverStone Health.

This guide covers the state and county steps outside Billings and the Billings Building Division for work inside the city. The Billings page lists the state Building Codes Division at 406-841-2051, but a county handout gives a different number, so confirm it with the state. Laurel was not checked for this guide, so contact the city directly.

What requires a permit in Yellowstone County?

The county’s floodplain regulations apply to all lands in its jurisdiction, so check with the Floodplain Office before building. Within the Zoning Jurisdictional area, zoning compliance, fence and sign permits are reviewed by the City/County Planning Division. New septic permits start with a Permit Tracking Sheet from the Yellowstone County Courthouse, Room 305.

Montana adopts one building code, based on the 2024 International Codes from 26 September 2026; a certified local program or the state Building Codes Program enforces it, and the state code does not reach houses of fewer than five units, farm and ranch buildings or private garages unless a local government has made it apply to them. How Montana’s statewide code works

Who handles permitting in Yellowstone County?

Zoning, floodplain and septic in Yellowstone County

Zoning

The county’s zoning jurisdiction outside Billings extends to a 4.5 mile zoning boundary. All Planning Division applications go through the CityView portal. The Consolidated Yellowstone County Zoning Commission meets the second Thursday of each month at 4:00pm at Billings City Hall, 316 N 26th Street.

Floodplain

Completed floodplain permits go to the Yellowstone County Courthouse or to the Floodplain Administrator. The county’s flood maps rest on the FEMA Flood Insurance Study with FIRMs dated November 6, 2013. As a Class 8 Community Rating System community (2004 - present), homeowners buying flood insurance get a 10% premium discount.

Septic and land division

The Permit Tracking Sheet confirms an address, an approach permit and that the lot is not in a floodplain; the sheet, a lot layout and the fee then go to RiverStone Health. An unfinished basement counts as one bedroom. Subdivision and certificate-of-survey parcels under 20 acres go through Montana DEQ sanitation review; parcels of 20 acres or more get local review by RiverStone Health, which may take up to 55 days.

Road approaches

The county approach standard allows a maximum 30' residential and 50' commercial approach width.

Yellowstone County permit costs and fees

Each floodplain permit or variance application carries a non-refundable $50.00 processing fee.

Where the state issues the permit, the fee follows a valuation table and plan review is 35 percent of the permit fee; a certified local program sets its own schedule. Montana’s state permit rules

How to get a permit in Yellowstone County

Where the state issues the permit, plan review averages about three weeks, and the building permit must be issued before any trade permit. Montana’s state permit rules

Inspections in Yellowstone County

New and repaired septic systems must be inspected by RiverStone Health Environmental Health Services at installation. Inside Billings, the Building Division requires online submission of all permits through CityView, and building inspections are requested by email or by calling 406.657.8270. Billings fences between four (4) and six (6) feet need a permit from Planning, while fences of 8 feet or more need a building permit.

Official Yellowstone County permitting resources

These are the primary sources behind this guide. Codes, fee schedules and procedures change — confirm the position for your filing date.

• Billings: outside city limits
• City/County Planning Division
• Consolidated Yellowstone County Zoning Commission
• Yellowstone County floodplain permits
• RiverStone Health septic permits
• Billings Building Division

Frequently asked questions

Does Billings issue permits outside the city limits?

No. Billings has not issued building, plumbing, mechanical or electrical permits outside the city limits since October 1, 2003; certain permits there come from the State Building Codes Division.

How far does county zoning reach outside Billings?

To a 4.5 mile zoning boundary.

Where does a new septic permit start?

With a Permit Tracking Sheet from the Yellowstone County Courthouse, Room 305, then RiverStone Health.

Simplify Yellowstone County permitting with Alliance Permitting

• Confirm whether the parcel is inside Billings or under the state program
• Prepare the CityView zoning, floodplain and septic tracking paperwork
• Track the state or city permit and the RiverStone Health inspection

Alliance Permitting is a permit documentation and submission company in Montana. We prepare your paperwork, file it correctly and coordinate with the permitting authority through issuance. We are not a contractor and we do not perform licensed plan review or inspections; that work stays with your licensed team and the jurisdiction.

This guide is provided by Alliance Permitting for general information about Yellowstone County permitting. Requirements, fees, and procedures change; confirm details with the permitting authority before relying on them.