The Mass General Hospital Blood Draw Lab - Chelsea is open to Mass General Brigham patients with an open laboratory order from their Mass General Brigham provider. No laboratory appointments are required for blood draws. The blood draw lab is open Mondays and Wednesdays from 8:00 am to 7:00 pm, Tuesdays and Thursdays from 8:00 am to 8:00 pm, Fridays from 8:00 am to 5:00 pm, and Saturdays from 8:00 am to 11:30 am. The blood draw lab is closed on holidays.