Montana (MT) Plumbing Code & Permit Rules
International Plumbing Code (2021) · Updated 2026-05-31
Data: State plumbing boards, ICC, IAPMO, EPA Last verified: 2026-05-31
Montana allows homeowner DIY plumbing with permits, though annual backflow testing is still required. This balanced approach gives homeowners flexibility while maintaining water quality standards.
Plumbing Code
Montana follows the International Plumbing Code (2021 edition).
Key Regulations
| Regulation | Status | Details |
|---|---|---|
| Plumbing Code | IPC (2021) | International Plumbing Code |
| Homeowner DIY | Allowed | Permissive; homeowner can do own work on primary residence |
| Water Heater Permit | Required | One of the more permissive states; own home only, not rental/spec |
| Backflow Testing | Annual, required | |
| Seismic Strapping | Not required | Water heater restraint |
DIY Plumbing in Montana
Montana allows homeowners to perform plumbing work on their primary residence. A permit is required for most work beyond minor repairs.
Common DIY-allowed projects (with permit):
- Replacing faucets and fixtures
- Installing shut-off valves
- Replacing toilet components
- Minor drain repairs
Projects that typically require a licensed plumber:
- New water line installation
- Sewer line repair or replacement
- Gas line connections
- Backflow preventer installation
Backflow Prevention
Montana requires annual backflow testing to protect the public water supply from contamination. Testing must be performed by a Certified tester.
Non-compliance penalty: Water service may be shut off if testing is not completed on schedule.
Water Conservation Requirements
Montana follows federal water conservation standards. Federal minimums apply
Lead Service Line Replacement
Montana has an active lead service line replacement program. Following EPA Lead and Copper Rule 2021
Data Sources
- Montana state plumbing board and licensing agency
- International Code Council (ICC)
- IAPMO
- EPA Safe Drinking Water Act
Updated as regulations change.
Need a licensed plumber in Montana?
Plumbing regulations vary by city. Connect with a licensed professional who knows your local code requirements.
Find a Licensed Plumber →Frequently Asked Questions
What plumbing code does Montana follow?
Montana follows the International Plumbing Code (2021 edition).
Can I do my own plumbing work in Montana?
Yes, homeowners in Montana can perform plumbing work on their primary residence with proper permits.
Do I need a permit to replace a water heater in Montana?
Yes, Montana requires a permit for water heater replacement. Homeowners may be able to do the work themselves with a permit.
Is backflow testing required in Montana?
Yes, Montana requires annual backflow testing.
Does Montana require seismic strapping for water heaters?
No, Montana does not require seismic strapping for water heaters. However, they remain a prudent option in areas with seismic activity.