Since D.O.s are not required to take the COMLEX, many do not have USMLE scores to report. You can apply with just COMLEX scores as many in my class did. The application does ask you if you took the USMLE, however. Unless you are applying to really competitive residencies, it really isn't worth the money to take both tests.
The tricky thing is that there is no place to enter your COMLEX scores. The trick that our school used was to scan it in as the last page of the transcript or have it reported on your transript.
