Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.

Seth Y Flagg, MD

Individual provider Hospitalist Physician · NPI 1548305451

Seth Y Flagg, MD is a Family Practice in Upper Marlboro, Maryland. Graduated from Tufts University School of Medicine in 2006, 20 years ago. Practices with Kaiser Foundation Health Plan of the Mid Atlantic States, Inc, a 1,934-clinician group, accepts Medicare assignment and offers telehealth. Licensed in Maryland.

Years since qualifying
20
Trained at
Tufts University School of Medicine
Licensed in
MD
In the registry since
2007
Specialties on file
2
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

See every abbreviation used in this directory →

Practice location Address checks out

1221 Mercantile Ln
Upper Marlboro, MD 20774-5374
Phone: (240) 672-3190
Show map & directions

Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Family Medicine Physician (primary) Taxonomy 207Q00000X · Licence 0082488 (MD)
Hospitalist Physician Taxonomy 208M00000X · Licence 0082488 (MD)

Record details

NPI number1548305451
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedFebruary 20, 2007
Last updated in NPPESJune 26, 2021
Certification dateJune 26, 2021
Mailing address2101 E Jefferson St Ste 6w, Rockville, MD 20852-4908

Medicare enrollment

From the CMS Doctors & Clinicians file — this clinician is enrolled in Medicare.

Medicare specialtyFAMILY PRACTICE
Medical schoolTUFTS UNIVERSITY SCHOOL OF MEDICINE
Graduated 2006 (20 years in practice)
Group practice Kaiser Foundation Health Plan Of The Mid Atlantic States, Inc — 1934 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
TelehealthOffers telehealth services