Gregory Leroy Walker, MD
Internal Medicine Physician · Baltimore, MD
Gregory Leroy Walker, MD is an internal medicine physician with a practice address in Baltimore, Maryland, and NPI 1366508301, issued on Dec 27, 2006. Check the license (Maryland D0025662, as entered in NPPES) on the Maryland Board of Physicians; the Medicare figures below come from public CMS files.
- Name
- Gregory Leroy Walker
- Credential
- MD
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- D0025662 MD
Self-reported in NPPES; status is on the state search - Practice location
- 3333 N Calvert St Ste 585, Baltimore, MD 21218
- Phone
- (410) 235-8858
- Enumerated
- Dec 27, 2006
- Record last updated
- Nov 19, 2021 (not updated in 5 years: call before relying on the address or phone)
- Fax
- (410) 235-8904
- Medicaid ID
- 771001100 MD
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 3,904 in Maryland → Look up another NPI →
Verify Gregory Leroy Walker in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMaryland Board of Physicians
Search for license D0025662Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
37% fewer Medicare Part D claims than the average internal medicine physician in 2024
1,988 Medicare Part D claims for 105 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 16% of claims. 260 claims were for opioids.
Most prescribed
- Oxycodone Hcl124 claims
- Losartan Potassium95 claims
- Atorvastatin Calcium62 claims
- Tramadol Hcl58 claims
- Alprazolam57 claims
- Gabapentin47 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.
Industry payments in 2024: $2,687.97
98 payments; by number, the most common kind was food and beverage; the largest payer was AstraZeneca Pharmaceuticals LP. 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.
Gregory Leroy Walker among 3,904 internal medicine physician records in Maryland
Gregory Leroy Walker, MD 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 2006, is newer than 9% of them.
- NPI issued2006 · 9% of these records are older, 55% newer
- In a Medicare fileYes · 77% of these records are
- In the CMS Doctors and Clinicians fileNo · 63% of these records are
- 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 →
The 8 internal medicine physician records with the nearest ZIP codes
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- Veronica Epstein, M.D.Baltimore, MD 212181962465195
- Miguel Karacuschansky, M.D.Baltimore, MD 212181467560383
- Theresa Lorch, M.D.Baltimore, MD 212181104888122
- James Phong Luong, M.D.Baltimore, MD 212181104938521
- Hassan Nasser, M.D.Baltimore, MD 212181912961665
Common questions
What is Gregory Leroy Walker, MD's NPI number?
Gregory Leroy Walker, MD's National Provider Identifier (NPI) is 1366508301, issued on Dec 27, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Gregory Leroy Walker, MD located?
The NPPES record lists a practice address at 3333 N Calvert St Ste 585, Baltimore, MD, 21218. Phone: (410) 235-8858. Providers update this record themselves, so call before visiting.
How can I verify Gregory Leroy Walker, MD's license?
NPPES lists Maryland license number D0025662, 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 Gregory Leroy Walker, MD prescribe under Medicare Part D?
In 2024, Gregory Leroy Walker, MD had 1,988 Medicare Part D claims for 105 beneficiaries; the average among internal medicine physician prescribers was 3,176. 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.