If you are working toward a four-year degree, you will meet the part of the definition of an eligible student defined as “has not completed the first four years of post-secondary education as of the beginning of the taxable year”. The fact that you have taken more than 4 years working toward the degree is not what is being measured. The fact that you have not completed it yet is what is being measured.
However, it is important to keep in mind that you can only take the American Opportunity Credit for 4 years. If you have taken the credit 4 times, you are no longer eligible even if you have not earned a four year degree in that time.
