Margretta Diemer, M.D.
NPI 1669543252 · Internal Medicine Physician · Bethesda, MD
Enrolled with Medicare as Order and Referring Only - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Margretta Diemer, M.D. is a Internal Medicine Physician provider in Bethesda, MD (NPI 1669543252).
Provider details
- NPI number
- 1669543252
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Female
- Sole proprietor
- No
- License
- 0101034873 (VA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
19 yrs in NPPES registry
- Profile completeness38% of score
100% of core fields populated
- Practice footprint23% of score
1 documented practice location
Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-11-13
- Last updated
- 2023-11-16
- Certified
- 2023-11-16
Frequently asked questions
- What is Margretta Diemer's NPI number?
- Margretta Diemer's National Provider Identifier (NPI) is 1669543252, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Margretta Diemer's specialty?
- Margretta Diemer is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Margretta Diemer located?
- Margretta Diemer's practice location on file with NPPES is Wrnmmc, Pcmh, Bldg 19, Bethesda, MD 20889-0001.
- What is Margretta Diemer's phone number?
- The practice phone number listed in the NPPES registry for Margretta Diemer is (301) 319-4326.
- Does Margretta Diemer accept Medicare?
- Margretta Diemer is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Margretta Diemer's NPI active?
- Yes — Margretta Diemer's NPI (1669543252) is active in the NPPES registry as of the last update on 2023-11-16.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.