NPPES file of Aug 9, 2026

William Hemsley Merwin, M.D.

Student in an Organized Health Care Education/Training Program · Baltimore, MD

William Hemsley Merwin, M.D. is a student in an organized health care education/training program with a practice address in Baltimore, Maryland, and NPI 1043697600, issued on May 4, 2015. Check the license (Maryland D0091613, as entered in NPPES) with the Maryland board that licenses this profession; the Medicare figures below come from public CMS files.

Record from CMS NPPES, file of Aug 9, 2026 · Medicare files 2024 · method · Verify with CMS →

NPPES recordNPPES file of Aug 9, 2026
1043697600
Name
William Hemsley Merwin
Credential
M.D.
Primary taxonomy
Student in an Organized Health Care Education/Training Program 390200000X
License number
D0091613 MD
Self-reported in NPPES; status is on the state search
Practice location
201 E University Pkwy Dept OF, Baltimore, MD 21218
Phone
(410) 554-2284
Enumerated
May 4, 2015
Record last updated
Jun 11, 2025
Fax
(410) 554-2184
Medicare enrollment
Enrolled (PECOS I20210614002598); accepts Medicare assignment
Medical or professional school
Georgetown University School Of Medicine, 2015
Entity
Type 1 · individual
Public record from CMS NPPES (open it on the CMS NPI Registry). Enrollment, assignment, school and telehealth: CMS Doctors and Clinicians file, Aug 2026. A record is not a license: verify it with the state board.
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Also registered at 201 E University Pkwy Dept OF

A shared address usually means a shared clinic or building; it does not show who employs whom.

  1. Ahmed Abdelhalim, MDStudent in an Organized Health Care Education/Training Program1033905559
  2. Olaitan Adeyoola, MBBSStudent in an Organized Health Care Education/Training Program1649112590
  3. Marwan Ahmed, MDStudent in an Organized Health Care Education/Training Program1518717610
  4. Natalie Akoto, MBCHBStudent in an Organized Health Care Education/Training Program1548011448
  5. Basem Al AchrasInternal Medicine Physician1114555026
  6. Saif Almushhadani, MDStudent in an Organized Health Care Education/Training Program1376048306

Verify William Hemsley Merwin in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersWhich Maryland board licenses this profession
    Search for license D0091613
    Check the board
  3. 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
  4. 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
  5. 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Find the Maryland license search

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79% more Medicare Part D claims than the average student in an organized health care education/training program in 2024

332 Medicare Part D claims for 55 beneficiaries, against an average of 185 among the 59,748 providers of this specialty who prescribed in Part D. Brand-name drugs were 62% of claims.

  1. William Merwin332
  2. Specialty average185

Most prescribed

  1. Albuterol Sulfate Hfa59 claims
  2. Trelegy Ellipta36 claims
  3. Prednisone24 claims
  4. Symbicort22 claims
  5. Montelukast Sodium15 claims
  6. Amoxicillin-Clavulanate Potass14 claims

Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.

Bills Medicare through one group practice

  1. Medstar Medical Group II LLCGlen Burnie, MD

Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).

William Hemsley Merwin among 5,632 student in an organized health care education/training program records in Maryland

William Hemsley Merwin, M.D. is one of 5,632 student in an organized health care education/training program records with a practice address in Maryland. 26% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2015, is newer than 7% of them.

  • NPI issued2015 · 7% of these records are older, 91% newer
  • In a Medicare fileYes · 26% of these records are
  • In the CMS Doctors and Clinicians fileYes · 2% of these records are
  • Graduated2015 · median 2019 among the 126 with a school on file
  • Record last updated2025 · 24% of these records were not updated in five years or more

Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 390200000X and a Maryland practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).

4,028 student in an organized health care education/training program records list a practice address in Baltimore

They are 4,028 of the 35,183 NPPES records with a practice address in Baltimore, and 5,632 student in an organized health care education/training program records in Maryland.

The 8 student in an organized health care education/training program records with the nearest ZIP codes

  1. Shadi Al Bahri, MDBaltimore, MD 212181447489380
  2. Abdullah AlawadBaltimore, MD 212181285058529
  3. Karim Chahine, MDBaltimore, MD 212181750537429
  4. Marcela Davalos Bichara, M.D.Baltimore, MD 212181477997286
  5. Trude FosterBaltimore, MD 212181649533449
  6. Mohammadali Habibi, M.D.Baltimore, MD 212181417274820
  7. Preston Jones, MDBaltimore, MD 212181417138934
  8. Arleen Lamba, MDBaltimore, MD 212181396927778

Common questions

What is William Hemsley Merwin, M.D.'s NPI number?

William Hemsley Merwin, M.D.'s National Provider Identifier (NPI) is 1043697600, issued on May 4, 2015. An NPI identifies a provider in billing; it is not a license.

Where is William Hemsley Merwin, M.D. located?

The NPPES record lists a practice address at 201 E University Pkwy Dept OF, Baltimore, MD, 21218. Phone: (410) 554-2284. Providers update this record themselves, so call before visiting.

How can I verify William Hemsley Merwin, M.D.'s license?

NPPES lists Maryland license number D0091613, as entered by the provider. Search the Maryland board that licenses this profession; the NPPES record confirms identity only.

How much does William Hemsley Merwin, M.D. prescribe under Medicare Part D?

In 2024, William Hemsley Merwin, M.D. had 332 Medicare Part D claims for 55 beneficiaries; the average among student in an organized health care education/training program prescribers was 185. Part D covers Medicare prescriptions only.

Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.

Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.