Tax Year Prior to 2020: Can I just estimate my cost since it is way more than what will be allowed by the IRS for a new natural gas furnace and air conditioner blower motor fan for $5216?

[twolfe888]

I can't find the bill, but I know the amount, so I don't know how it was itemized, or if it matters

[KarenL2]

Since it is more than allowed, you can use your best guess.  Just keep in mind that, if questioned, you will need to produce a copy of the bill (perhaps you could get that from the company you purchased it from).  Also, make sure your unit qualifies.

You can see which energy-saving home improvements qualify for a federal tax credit at the Energy Star website.

The Residential Energy Efficient Property Credit is what is called a "non-refundable" credit which means it will only reduce your tax liability to zero.  Any remainder can be carried forward to the next year. 

This link has more information about the IRS Home Energy Credits .