Is my son eligible to receive the American Opportunity Credit if I earn in excess of $90K/year?

My son is in the process of getting his bachelors degree. He's a full time student at the UMN. I'm married, filing jointly. I make in excess of $90k/year. Turbotax program claims my son is eligible to receive the American Opportunity Credit but I don't understand how that is possible given my income level. Please explain.