I am not certain I understand your question. If you matched to a PGY-1 position for this July and now want to participate again, the answer is yes as long as you did not also match to a PGY-2 position (an "Advanced" match) for next year. Even if you matched to a 3 year categorical program, your match commitment is only to start your PGY-1 year -- you can resign at the end of the year if you wish.