William R. Grier, M.D
Internal Medicine Physician · Baltimore, MD
William R. Grier, M.D is an internal medicine physician with a practice address in Baltimore, Maryland, and NPI 1740643378, issued on Mar 31, 2016. Check the license (Maryland D91153, as entered in NPPES) on the Maryland Board of Physicians; the Medicare figures below come from public CMS files.
- Name
- William R. Grier
- Credential
- M.D
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- D91153 MD
Self-reported in NPPES; status is on the state search - Practice location
- 22 S Greene St, Baltimore, MD 21201
- Phone
- (410) 328-6110
- Enumerated
- Mar 31, 2016
- Record last updated
- Dec 20, 2021 (not updated in 5 years: call before relying on the address or phone)
- Medicare enrollment
- Enrolled (PECOS I20210928002211); accepts Medicare assignment
- Medical or professional school
- Drexel University College Of Medicine, 2016
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 3,904 in Maryland → Look up another NPI →
Also registered at 22 S Greene St
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify William R. Grier in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMaryland Board of Physicians
Search for license D91153Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
91% fewer Medicare Part D claims than the average internal medicine physician in 2024
270 Medicare Part D claims for 54 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 67% of claims.
Most prescribed
- Trelegy Ellipta62 claims
- Albuterol Sulfate Hfa51 claims
- Prednisone19 claims
- Breo Ellipta18 claims
- Levalbuterol Tartrate Hfa17 claims
- Varenicline Tartrate11 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.
The practice group's MIPS final score for 2023 (Medicare payment program): 100 of 100
The Merit-based Incentive Payment System score is reported for the practice group, not for one clinician alone. Four categories are weighted into the final score; the average among 454,083 clinicians with a measured score was 83.5.
Source: CMS Quality Payment Program, MIPS performance year 2023, group reporting; category weights for 2023 (qpp.cms.gov).
Industry payments in 2024: $875.00
2 payments; by number, the most common kind was consulting fee; the largest payer was Merck Sharp & Dohme LLC. The 50,334 providers of this specialty with any payment received $1,303.06 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.
Bills Medicare through one group practice
- University OF Maryland Physicians PABaltimore, MD
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
William R. Grier among 3,904 internal medicine physician records in Maryland
William R. Grier, M.D is one of 3,904 internal medicine physician records with a practice address in Maryland. 77% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2016, is newer than 79% of them.
- NPI issued2016 · 79% of these records are older, 19% newer
- In a Medicare fileYes · 77% of these records are
- In the CMS Doctors and Clinicians fileYes · 63% of these records are
- Graduated2016 · median 2003 among the 2,445 with a school on file
- Record last updated2021 · 59% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207R00000X and a Maryland practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
1,278 internal medicine physician records list a practice address in Baltimore
They are 1,278 of the 35,183 NPPES records with a practice address in Baltimore, and 3,904 internal medicine physician records in Maryland.
All 3,904 in Maryland → Every provider in Baltimore → Internal Medicine Physician nationwide →
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Common questions
What is William R. Grier, M.D's NPI number?
William R. Grier, M.D's National Provider Identifier (NPI) is 1740643378, issued on Mar 31, 2016. An NPI identifies a provider in billing; it is not a license.
Where is William R. Grier, M.D located?
The NPPES record lists a practice address at 22 S Greene St, Baltimore, MD, 21201. Phone: (410) 328-6110. Providers update this record themselves, so call before visiting.
How can I verify William R. Grier, M.D's license?
NPPES lists Maryland license number D91153, as entered by the provider. Search the Maryland Board of Physicians at https://www.mbp.state.md.us/. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does William R. Grier, M.D prescribe under Medicare Part D?
In 2024, William R. Grier, M.D had 270 Medicare Part D claims for 54 beneficiaries; the average among internal medicine physician prescribers was 3,176. Part D covers Medicare prescriptions only.
What is William R. Grier, M.D's MIPS final score?
The 2023 MIPS final score is 100 of 100, reported for the practice group. The average among 454,083 clinicians with a measured score was 83.5.
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.