State tax filing

Hello PattiF. Followed your instructions. In round numbers I got a 9,000 tax credit in 2020. Amended for the actually cost decreased the credit to 6,000. My understanding is that I should report the difference, ie, 3,000, as income in 2021. 

I want to make sure i understood this correctly because it makes me uneasy. I saved 3,000 in taxes in 2020 because i did not get the energy company rebate until 2021.  when i report the 3,000 as income, that will add taxes in 2021 of 3000 x 0.24 (my tax bracket) = $720. Is this right? 

thank you