This means that the physician has gone through an AOA approved residency and training as well as gone to a DO school and passed those exams specificed for certification, meaning COMLEX and specialty boards. This usually involves an internship year, which is usually incorporated into the residency program training. The AOA is considering allowing members to "come back into the fold" to being AOA members after completing a ACGME residency, but I'm not sure if that is official yet....