No, I think they only take visa or MC. I wanted to use my Discover to buy their latest MSAR but I had to use my Visa. Wait about 10 years and AMCAS may catch on to the fact that there are actually more than two credit card companies in the U.S.
I could be wrong, but I don't think they did last year. I tried to use that too for the bucks back but ended up using a Visa. Maybe they will be accepting it this year.