The American Opportunity Education Credit is available to be claimed 4 times per eligible student. This includes the number of times you claimed the Hope Education Credit (which was used for tax years prior to 2009).
For example: If you claimed the Hope Education Credit on your 2017 tax return and then claimed the American Opportunity Credit on your 2018, 2019, and 2020 tax returns, you will not be eligible to claim the American Opportunity Credit on your 2021 tax return. Your other education credit/deduction options would be the Lifetime Learning Credit. If you cannot claim the education credit, you can also use the Tuition and Fees Deduction.
Please note that you are unable to claim more than one education credit for the same student in the same year.