Pub 970 page 21
https://www.irs.gov/pub/irs-pdf/p970.pdf
"Refundable Part of Credit
Forty percent of the American opportunity credit is refundable for most taxpayers. However, if you were under age
24 at the end of 2020 and the conditions listed below apply to you, you can't claim any part of the American opportunity credit as a refundable credit on your tax return.
Instead, your allowed credit (figured on Form 8863, Part II)
will be used to reduce your tax as a nonrefundable credit
only.
You don't qualify for a refund if items 1 (a, b, or c), 2,
and 3 below apply to you.
1. You were:
a. Under age 18 at the end of 2020, or
b. Age 18 at the end of 2020 and your earned income (defined below) was less than one-half of
your support (defined below), or
c. Over age 18 and under age 24 at the end of 2020
and a full-time student and your
earned income was less than
one-half of your support .
2. At least one of your parents was alive at the end of
2020.
3. You are filing a return as single, head of household,
qualifying widow(er), or married filing separately for
2020."
Incidentally, if "college savings account" refers to a QTP / 529 / ESA that is (most likely) not self support.
The treatment of expenses paid with distributions from Sec. 529 plans and Coverdell ESAs in the support test is uncertain because of the dual nature of these college savings vehicles and a lack of IRS guidance. The consensus among tax experts is that it is parental support, because the parent is the owner of the plan. It might be helpful, to the case, to make distributions to the beneficiary or school, rather than the owner.
https://ttlc.intuit.com/questions/3402602-can-i-claim-money-from-a-529-fund-as-my-supporting-my-22-y...
