MedStar Medical Group at St. Mary’s


Family Medicine | Internal Medicine | Pediatrics

Care you can trust.

Don't delay medical care. We are open for in-person office visits and video visits. Call us to schedule your appointment today.

Call: 301-997-0055

41680 Miss Bessie Dr., Ste. 301
Leonardtown, MD 20650

Hours of Operation:

Monday through Friday: 8 a.m. to 5 p.m.

Phone Hours:

Monday through Friday: 8 a.m. to 5 p.m.


Care you can trust

Your health and safety are always our top priority. Here's what you can expect from an in-office visit:

  • Face masks required for everyone, regardless of symptoms
  • Frequent disinfecting and cleaning of public spaces and exam rooms, including after every clinical visit
  • Staggered appointments to minimize people in a given area
  • Screening all patients and visitors for symptoms upon arrival
  • Physical distancing with floor markers and reconfigured waiting areas
  • Sanitizing stations throughout the facility

We offer internal medicine family medicine, and pediatric care in Leonardtown, MD. Our board-certified physicians and nurse practitioners treat patients of all ages—from newborns to geriatric patients.

We believe maintaining a long-term relationship with a primary care medical provider is essential to your overall well-being. Our providers can help you establish and maintain good health, stay up-to-date on vaccines, conduct routine health screenings and checkups, and manage chronic conditions or diseases.

Meet the Team


James Boyd, MD, internal medicine

James Boyd, MD
Internal Medicine

Sarah Johnson, MD, pediatrics

Sarah Johnson, MD
Internal Medicine

Maria O'Brien, MD, family medicine

Maria O’Brien, MD
Family Medicine

Ashley Dearstine, CRNP, family medicine

Ashley Dearstine, CRNP
Family Medicine

Ashley O'Neil, CRNP, family medicine

Ashley O’Neil, CRNP
Family Medicine

Katherine Vachalek, CRNP, family medicine

Katherine Vachalek, CRNP
Family Medicine

Tiffany Wilson, CRNP, family medicine

Tiffany Wilson, CRNP
Family Medicine



Need urgent care?

We bring together top providers at community-based locations.

Need care after hours?

We offer virtual access to medical providers from your home.

Looking for specialty care?

We bring together the top specialists in your community.

Insurance plans we accept

MedStar Medical Group accepts most major health insurance plans. If you are uncertain as to whether your individual health insurance plan is accepted at MedStar Medical Group, please call your insurance company.

Click here for a list of accepted insurance plans.

Services we offer include:

  • Annual physicals and sports physicals
  • Chronic disease screening and management
  • Flu care and flu vaccine
  • Geriatrics
  • Laboratory testing and blood tests
  • Pediatric Care
  • Preoperative consultations
  • Vaccines and immunizations
  • Weight loss assistance


Patient-Centered Medical Home™ is a trademark of the National Committee for Quality Assurance.

MedStar Medical Group at St. Mary’s has been awarded Patient-Centered Medical Home™ recognition by the National Committee for Quality Assurance (NCQA). The NCQA Patient-Centered Medical Home standards emphasize the use of systematic, patient-centered, coordinated care that supports access, communication, and patient involvement.

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