NPPES file of Aug 9, 2026

John Robyn V. Diez, MD

Addiction Medicine (Internal Medicine) Physician · Oakland, MD

John Robyn V. Diez, MD is an addiction medicine (internal medicine) physician with a practice address in Oakland, Maryland, and NPI 1942881909, issued on Apr 20, 2021. Check the license (Maryland D0102636, as entered in NPPES) on the Maryland Board of Physicians; 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
1942881909
Name
John Robyn V. Diez
Credential
MD
Primary taxonomy
Addiction Medicine (Internal Medicine) Physician 207RA0401X
License number
D0102636 MD
Self-reported in NPPES; status is on the state search
Practice location
69 Wolf Acres Dr, Oakland, MD 21550
Phone
(301) 533-2190
Enumerated
Apr 20, 2021
Record last updated
Aug 25, 2025
Medicare enrollment
Enrolled (PECOS I20250404000628); accepts Medicare assignment
Telehealth
Offers telehealth (CMS)
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 69 Wolf Acres Dr

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

  1. Heather BosleyClinical Social Worker1114798402
  2. Sara Cockerham, LCSW-CClinical Social Worker1457900052
  3. Brianna Graham, LMSWSocial Worker1801722723
  4. Paul Miller, D.O.Family Medicine Physician1194727487
  5. Angela Sisler, LCSW-CClinical Social Worker1972133882

Verify John Robyn V. Diez in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersMaryland Board of Physicians
    Search for license D0102636
    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
Open the Maryland license search

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90% fewer Medicare Part D claims than the average addiction medicine (internal medicine) physician in 2024

82 Medicare Part D claims, against an average of 829 among the 401 providers of this specialty who prescribed in Part D. Brand-name drugs were 0% of claims.

  1. John Robyn Diez82
  2. Specialty average829

Most prescribed

  1. Buprenorphine-Naloxone39 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. Specialty Physicians OF Garrett County, LLCOakland, MD

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

Addiction Medicine (Internal Medicine) Physician providers in Maryland

There are 15 addiction medicine (internal medicine) physician records in Maryland.

Other addiction medicine (internal medicine) physician records in Maryland

  1. Alia Bodnar, M.D.Baltimore, MD1043535123
  2. Megan Buresh, M.D.Baltimore, MD1710257290
  3. Cassandra Chioma, MDBaltimore, MD1356846968
  4. Howard Cohen, MDBaltimore, MD1770575326
  5. Fidelis Define, MDTowson, MD1245474063
  6. Terrence Fitzgerald, M.D.Baltimore, MD1881683522
  7. Michael Hayes, MDBaltimore, MD1871566125
  8. Bradley Levin, M.D.Easton, MD1629071360
  9. Arthur Marsh, M.D.Salisbury, MD1437297512
  10. Lia PennBaltimore, MD1376162768

Common questions

What is John Robyn V. Diez, MD's NPI number?

John Robyn V. Diez, MD's National Provider Identifier (NPI) is 1942881909, issued on Apr 20, 2021. An NPI identifies a provider in billing; it is not a license.

Where is John Robyn V. Diez, MD located?

The NPPES record lists a practice address at 69 Wolf Acres Dr, Oakland, MD, 21550. Phone: (301) 533-2190. Providers update this record themselves, so call before visiting.

How can I verify John Robyn V. Diez, MD's license?

NPPES lists Maryland license number D0102636, 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 John Robyn V. Diez, MD prescribe under Medicare Part D?

In 2024, John Robyn V. Diez, MD had 82 Medicare Part D claims; the average among addiction medicine (internal medicine) physician prescribers was 829. 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.