Montana (MT) Plumbing Code & Permit Rules
International Plumbing Code (2021)
Data: State plumbing boards, ICC, IAPMO, EPA
Check Montana and local rules for homeowner plumbing permits and backflow testing requirements.
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 is subject to EPA lead service line inventory and replacement requirements.
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) as of our last review; state and local amendments may apply.
Can I do my own plumbing work in Montana?
Homeowners in Montana may be allowed to do plumbing work on their primary residence; check state and local permit rules before starting.
Do I need a permit to replace a water heater in Montana?
Permit rules for water heater replacement in Montana depend on the state and your local jurisdiction; check with your local building department. Homeowners may be able to do the work themselves with a permit.
Is backflow testing required in Montana?
Backflow testing requirements in Montana depend on the state code and your water utility; check with your utility about which assemblies must be tested and how often.
Does Montana require seismic strapping for water heaters?
We have no statewide seismic strapping requirement for water heaters on record for Montana; local building codes may still require it, so check with your local building department. Strapping remains a prudent option in areas with seismic activity.