When you apply to an undergrad research position, be honest about your career path. For most lab positions, it won't matter if you are premed, pregrad, or headed for the job market after graduation, or undecided.
If your career path matters to the lab, and you aren't on the "preferred" track for a position, then you won't want to join the lab anyway. You want to join a lab that will help you meet your personal and professional goals.