Should my dependents only qualify for a partial American Opportunity Credit?

You can get a maximum annual credit of $2,500 per eligible student. If the credit brings the amount of tax you owe to zero, you can have 40 percent of any remaining amount of the credit (up to $1,000) refunded to you.

You can check Form 1040 line 24 (total tax), line 29 (American Opportunity Credit, refundable) and Schedule 3 line 3 (education credits):

1. Click on "Tax Tools" in the left menu
2. Click "Tools"
3. Click "View Tax Summary" in the Tool Center window
4. Click on "Preview my 1040" on the left

Please see What education tax credits are available? , Who is eligible to take the American Opportunity Tax Credit? and What expenses qualify for the American Opportunity Tax Credit? for additional information.

If this doesn't help you might have to review your entries carefully:

1. Login to your TurboTax Account 
2. Click on the Search box on the top and type “1098T”
3. Click on “Jump to 1098T”

You say there is $20K in box 1 of the 1098-T, but not what's in box 5.  Generally speaking, the difference between box 1 and box  5 is the qualified expenses for the American Opportunity Credit.  But there is a way around that.