Outpatient Lab

We are a College of American Pathologists (CAP) and American Association of Blood Banks (AABB) accredited lab that is a part of the Johns Hopkins Health System. To ensure that you have the best experience possible with the least amount of discomfort, all of our laboratory staff are certified phlebotomists and have many years of experience in the medical field. For your safety, all supplies used during your laboratory test are individually sealed and single-use only; we also are a latex-free lab.

Our normal hours of operation are Monday through Friday from 7:00am-3:00pm. No appointment is needed; we operate on a walk-in basis.* We are also open Saturday and Sunday from 7:00am-3:00pm for STAT testing (pre-op, infant bilirubin, infusion medicine, and/or a provider has ordered the test STAT/needed immediately) .

Orders may be faxed to 410-884-4834. If you have any questions regarding your order, you may call 410-740-7670. We make every attempt to see you quickly once you arrive. However, if something is missing from the prescription, we may have to contact your doctor's office (during business hours) to obtain an amended order. We apologize in advance for any delay this may cause.

Where to Go

Free parking is available in Visitor Lot C. Enter the hospital main entrance and check-in at the information desk. Proceed to your left past the gift shop and double elevators to the Bolduc Family Outpatient Center.

What to Bring

  • You will need to bring a valid picture ID, insurance information, and doctor's order. The doctor's order must have the date, doctor's signature, diagnosis code and tests needed.
  • For HIV AB testing, in addition to a valid order, you will need to bring a HIV consent form signed by both you and your doctor.


We participate with Medicare, Medicaid, Chase Brexton, Healthy Howard and most insurance companies, so please be sure to check with your insurance company before coming. HMOs usually require you to go to a free-standing lab.

How to Prepare

Some tests require a fasting specimen. For a complete list of requirements, it is best to check with your doctor. The most common fasting tests are fasting glucose and lipid panel, also known as coronary risk panel. These tests require eight hours of fasting. It is okay to drink water during the time you are fasting.

*Additional Information

  • We are able to collect samples for orders requiring blood, stool, and/or urine on site. For your comfort and convenience, we are also able to provide containers and directions for collecting the samples at home.
  • We are able to accept orders requiring swabs, sputum, or body fluids, but the samples must be collected by your doctor and brought to the lab.
  • If you have an order for a sweat chloride, this test takes about an hour and requires an appointment. Please contact the Lab to set up an appointment.
  • Gestational diabetes testing is only available Monday-Friday and you must arrive before 2pm for the one hour test and before noon for the three hour test. No appointment required.

For questions about types of samples not listed, or for any additional information about laboratory tests, please feel free to contact the Lab at 410-740-7655. We would be glad to help in any way to make your experience a positive one.