Blood tests are done at a doctor's offices and clinics or at a local lab, such as LabCorp or Quest Diagnostics, notes Fox News. As of 2015, LabCorp and Quest Diagnostics have locations in every U.S. state and the District of Columbia, state their respective websites.
The LabCorp website provides a search function that locates labs that provide the desired testing within up to 75 miles of the user's address. Online appointment scheduling is available, but appointments are not required. Some tests, such as employment drug screening, are done only at specific locations, LabCorp explains. Appointments and online scheduling are also available at Quest Diagnostics.