If you mean you're applying, getting accepted, then deferring matriculation, you should check with schools, because some "highly discourage" it. (I'd look in the msar or on their websites). I was thinking of doing that, but my top choice schools basically said they'd only let you defer if there was some massive family or personal crisis that prevented you from matriculating. so check first just in case! As for taking a year off before med school, I definitely recommend it! 🙂