There’s no carryover for this credit. The carryover would be for energy efficient alternative energy sources, such as solar power, geothermal, or wind. The credit for installing energy efficient windows does not carry over.
The credit for energy efficient windows was reinstated late in 2019 retroactive for 2018. A credit for windows installed in 2018 would have to be claimed by filing an amended 2018 tax return. The amount of the credit is 10% of the price of the windows, not including installation, and only if they meet Energy Star version 6.0 or higher certification. The maximum lifetime credit for all such improvements is $500 and the maximum lifetime credit for windows is $200, so if you ever took the credit in the past, your credit now might be limited.
