Michael F. Flessner, MD
Internal Medicine Physician · Frederick, MD
Michael F. Flessner, MD is an internal medicine physician with a practice address in Frederick, Maryland, and NPI 1669401857, issued on Jul 1, 2006. Check the license (Maryland D0035499, as entered in NPPES) on the Maryland Board of Physicians; the Medicare figures below come from public CMS files.
- Name
- Michael F. Flessner
- Credential
- MD
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- D0035499 MD
Self-reported in NPPES; status is on the state search - Practice location
- 100 S Market St, Frederick, MD 21701
- Phone
- (301) 600-1506
- Enumerated
- Jul 1, 2006
- Record last updated
- Dec 6, 2016 (not updated in 10 years: call before relying on the address or phone)
- Fax
- (301) 662-9079
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 3,904 in Maryland → Look up another NPI →
Also registered at 100 S Market St
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Maria Elena Adrianza-Tangrea, P.A. - C.Physician Assistant1891792081
- Urvisha Patel, PA-CPhysician Assistant1952235756
- Kimether Redmon, FNP-CPrimary Care Nurse Practitioner1861910143
- Tracee Tabares, FNPNurse Practitioner1033732995
- Jane Towers, PH.D.Family Nurse Practitioner1235242249
Verify Michael F. Flessner in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMaryland Board of Physicians
Search for license D0035499Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
98% fewer Medicare Part D claims than the average internal medicine physician in 2024
60 Medicare Part D claims for 11 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 0% of 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.
Michael F. Flessner among 3,904 internal medicine physician records in Maryland
Michael F. Flessner, 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 updated2016 · 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).
59 internal medicine physician records list a practice address in Frederick
They are 59 of the 3,981 NPPES records with a practice address in Frederick, and 3,904 internal medicine physician records in Maryland.
All 3,904 in Maryland → Every provider in Frederick → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Sajjad Aziz, MDFrederick, MD 217011457336554
- James Grissom, M.D.Frederick, MD 217011881695898
- Syed Haque, M.D.Frederick, MD 217011952390205
- Safrina Hasan, DOFrederick, MD 217011679524540
- Sibte Kazmi, MDFrederick, MD 217011861451361
- Jack Lu, M.D.Frederick, MD 217011982717765
- Yassin Mohamed, M.D.Frederick, MD 217011386752806
- John Piacentino, MDFrederick, MD 217011114936895
Common questions
What is Michael F. Flessner, MD's NPI number?
Michael F. Flessner, MD's National Provider Identifier (NPI) is 1669401857, issued on Jul 1, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Michael F. Flessner, MD located?
The NPPES record lists a practice address at 100 S Market St, Frederick, MD, 21701. Phone: (301) 600-1506. Providers update this record themselves, so call before visiting.
How can I verify Michael F. Flessner, MD's license?
NPPES lists Maryland license number D0035499, 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 Michael F. Flessner, MD prescribe under Medicare Part D?
In 2024, Michael F. Flessner, MD had 60 Medicare Part D claims for 11 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.