No, but it will make things hard. Much harder than low board scores. If you're a hardworking, likeable person whose grade was pulled down by, for example, a low shelf exam score; you can probably get rec letters for damage control. If you did a poor job on the wards, that will be harder to fix (unless you have a very good explanation - dying parent, etc.) Either way, you need attendings who will back your career either in the form of letters or phone calls to PD's. 4th year electives are a good way to get this support. Talk to the clerkship or program director at your school about where to go from here. With luck, they'll either give some tough love advice about finding another specialty or help you start polishing up an application.
