Recertification for a previous year

My dad was disallowed American Opportunity Tax Credit and other children related credits for 2017 when he filed in 2018. This was odd because he's been filing the same way and claiming the same credits for all our lives. This year 2019 when filing for 2018, he included form 8862 and was recertified for the credits for 2018. Would we be able to file form 8862 for 2017 retroactively to get the credits?

posted

You can get a maximum of $2500 American Opportunity Tax Credit per child and only for their first 4 years of college. It is possible that he has reached his maximum deduction.