1. Home
  2. Directory
  3. Maryland
  4. Bethesda
  5. Internal Medicine
  6. NPI Profile

MARGRETTA DIEMER M.D.
NPI 1669543252
Internal Medicine in Bethesda, MD

Active since November 13, 2006PECOS EnrolledAccepts Medicare Assignment
WRNMMC, PCMH, BLDG 19, 8901 WISCONSIN AVE, BETHESDA, MD 20889(301) 319-4326(301) 400-0618 Get Directions Write a Review

NPPES record last updated: November 16, 2023. Verified against the NPPES registry weekly; last sync: August 02, 2026.

About Margretta Diemer M.d. NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

MARGRETTA DIEMER M.D. (NPI 1669543252) is an individual internal medicine provider in Bethesda, Maryland, licensed in Virginia (0101034873) and active in the NPI registry since November 2006. She is enrolled in Medicare PECOS and is a graduate of Georgetown University School Of Medicine (1979).

NPPES Registry Identity

NPI1669543252
Entity TypeIndividualFemale
Primary Taxonomy207R00000X
Provider Legal NameMARGRETTA DIEMERCredential: M.D.
Location AddressWRNMMC, PCMH, BLDG 19, 8901 WISCONSIN AVEBethesda, MD 20889-0001
Mailing AddressWrnmmc, Pcmh, Bldg 19, 8901 Wisconsin AveBethesda, MD 20889-0001 · (301) 319-3471 · Fax (301) 400-0618
Phone(301) 319-4326
Fax(301) 400-0618
Sole ProprietorNo
Medical School CMSGeorgetown University School Of MedicineGraduated 1979
Enumeration DateNovember 13, 2006
Last NPPES UpdateNovember 16, 2023
NPPES CertifiedNovember 16, 2023
✔ NPI 1669543252 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal MedicineAllopathic & Osteopathic Physicians
Taxonomy Code207R00000X
License✔ Licensed in VA · 0101034873
Definition
A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults and the elderly. Internists are trained in the diagnosis and treatment of cancer, infections and diseases affecting the heart, blood, kidneys, joints and digestive, respiratory and vascular systems. They are also trained in the essentials of primary care internal medicine, which incorporates an understanding of disease prevention, wellness, substance abuse, mental health and effective treatment of common problems of the eyes, ears, skin, nervous system and reproductive organs.
WRNMMC, PCMH, BLDG 19, Bethesda, MD 20889
Open in Google Maps ↗

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, and ordering and referring status from the CMS PECOS system.

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Margretta Diemer M.d. is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.

PECOS PAC ID3274712351
PECOS Enrollment IDI20110120001107
Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 20889 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient
$147.85 typical visit price
range $65.18 – $194.86
Typical copayment $36.96 (range $16.29 – $48.71)
Most-billed visit code 99204
Established Patient
$113.72 typical visit price
range $21.40 – $158.88
Typical copayment $28.43 (range $5.35 – $39.72)
Most-billed visit code 99214
Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

Referred Medical Equipment & Supplies CMS DME claims 2

Durable medical equipment, devices and supplies this provider ordered from DME suppliers for patients, from Medicare fee-for-service claims.

Transport chair, adult size, patient weight capacity up to and including 300 pounds E1038
DME-Other DME · category DE000N
1 supplier11 claims11 services$9.75 avg. paid by Medicare
High strength, lightweight wheelchair K0004
DME-Wheelchairs · category DD000N
1 supplier11 claims11 services$27.52 avg. paid by Medicare
Dollar amounts are the average Medicare paid the supplier per service. They are not the cost to the patient.

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is Margretta Diemer's NPI number?

The NPI number for Margretta Diemer is 1669543252. It was assigned to this individual provider in the NPPES registry on November 13, 2006.

Where is Margretta Diemer located?

Margretta Diemer practices at Wrnmmc, Pcmh, Bldg 19 8901 Wisconsin Ave, Bethesda, MD 20889. The listed phone number is (301) 319-4326.

What is Margretta Diemer's specialty?

The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.

Is Margretta Diemer enrolled in Medicare?

Yes. Margretta Diemer is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.

When was this NPI record last updated?

The NPPES record for Margretta Diemer was last updated on November 16, 2023. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 2 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.