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

Dr. William Hemsley Merwin III, MD

Individual provider Internal Medicine Physician · NPI 1043697600

Dr. William Hemsley Merwin III, MD is a Hospitalist in Baltimore, Maryland. Graduated from Georgetown University School of Medicine in 2015, 11 years ago. Practices with Medstar Medical Group II LLC, a 3,717-clinician group and accepts Medicare assignment. Licensed in Maryland.

Years since qualifying
11
Trained at
Georgetown University School of Medicine
Licensed in
MD
In the registry since
2015
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

201 E University Pkwy Dept OF
Baltimore, MD 21218
Phone: (410) 554-2284
Fax: (410) 554-2184
Show map & directions

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

Specialties & licences

Student in an Organized Health Care Education/Training Program (primary) Taxonomy 390200000X (MD)
Internal Medicine Physician Taxonomy 207R00000X · Licence D0091613 (MD)

Record details

NPI number1043697600
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorYes
NPI enumeratedMay 4, 2015
Last updated in NPPESJune 11, 2025
Certification dateJune 11, 2025

Medicare enrollment

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

Medicare specialtyHOSPITALIST
Medical schoolGEORGETOWN UNIVERSITY SCHOOL OF MEDICINE
Graduated 2015 (11 years in practice)
Group practice Medstar Medical Group Ii Llc — 3717 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
Practice locations2 on file with Medicare

Other providers in Baltimore