Replacement Windows in Montana

Rebates & incentives

The federal window tax credit (25C) ended for projects placed in service after December 31, 2025. If your windows were installed in 2025, you can still claim it on your 2025 return — but for new projects there is no federal window credit. State and utility programs are now the main source of window incentives.

Montana's IRA Home Energy Rebates are administered by the Department of Environmental Quality (DEQ) Energy Bureau; DEQ submitted its implementation application in late 2024 and received a conditional award, but the programs remained in a pended, pre-launch status with no rebates available as of mid-2026. Under the whole-home HOMES pathway, replacement windows could count toward modeled energy savings rather than earning a standalone rebate. Confirm current status with Montana DEQ before promising rebates.

• NorthWestern Energy E+ (MT). NorthWestern Energy serves roughly 90% of Montana and its Efficiency Plus (E+) program offers residential rebates for measures such as insulation, HVAC and water heating; a dedicated replacement-window rebate is not a standard E+ offering, so confirm current measures directly. (NorthWestern Energy (northwesternenergy.com))
• Montana-Dakota Utilities (MDU) Residential Rebates. In its Montana service area MDU rebates high-efficiency furnaces, thermostats and LED lighting for existing homes; windows are not among the rebated measures. (Montana-Dakota Utilities (montana-dakota.com))

Energy code

Montana enforces a statewide residential energy code based on the 2021 IECC with state amendments (adopted in 2022), which sets prescriptive window U-factor limits for its cold, dry IECC zone 6B climate. Permitting and enforcement run through certified local jurisdictions, so check local requirements for replacement-window U-factors.

Local market research in Montana

• Replacement windows in Billings, MT covers costs, codes, rebates, and local FAQs.