On May 21, 2026, the US Environmental Protection Agency finalized a change to its Technology Transitions rule under the AIM Act. The change removes the January 1, 2026 deadline for installing residential and light-commercial air conditioning and heat pump systems that were manufactured or imported before January 1, 2025 using higher-GWP refrigerants such as R-410A.
In practice, equipment already in the supply chain can now be installed until supplies run out, rather than becoming stranded inventory.
What hasn’t changed
The underlying transition is still in place. Since January 1, 2025, new residential and light-commercial AC and heat pump systems using refrigerants with a GWP above 700 can no longer be manufactured or imported in the US. New equipment is shipping with lower-GWP A2L refrigerants such as R-454B and R-32.
Some states have their own rules, so the federal change doesn’t settle the question everywhere. New York, for example, has kept its own 2026 deadline.
What it means for projects
- Projects that bought R-410A equipment before 2025 have more flexibility on installation timing, subject to state rules.
- Most new specifications will still be written around A2L equipment, so design, installation and service practices for mildly flammable refrigerants remain the long-term direction.
- On mixed fleets, such as residences or campus buildings with both older and newer units, maintenance teams will be servicing two families of refrigerant for years to come.
As always, the right answer depends on the jurisdiction and the equipment involved. We review refrigerant requirements as part of preconstruction on every mechanical scope.
