Did your husband get a Form 1098-T from the school? You cannot claim the American Opportunity Credit without a 1098-T, except in some very unusual circumstances.
To claim the American Opportunity Credit the school has to be an "eligible educational institution." The following is from IRS Publication 970.
"An eligible educational institution is generally any accredited public, nonprofit, or proprietary (privately owned profit-making) college, university, vocational school, or other postsecondary educational institution. Also, the institution must be eligible to participate in a student aid program administered by the U.S. Department of Education."
"The educational institution should be able to tell you if it is an eligible educational institution."
Also, to claim the American Opportunity Credit the student must meet four requirements. One of the requirements is the following, again from IRS Publication 970.
"3. For at least one academic period beginning (or treated as beginning) in 2021, the student both:
a. Was enrolled in a program that leads to a degree, certificate, or other recognized educational credential; and
b. Carried at least one-half the normal full-time workload for his or her course of study.
The standard for what is half of the normal full-time workload is determined by each eligible educational institution. However, the standard may not be lower than any of those established by the U.S. Department of Education under the Higher Education Act of 1965."
