Mark Stephan Ostrem, MD
Geriatric Medicine (Internal Medicine) Physician · Quincy, MA
Mark Stephan Ostrem, MD is a geriatric medicine (internal medicine) physician with a practice address in Quincy, Massachusetts, and NPI 1811985633, issued on Oct 6, 2005. Check the license (Massachusetts 44501, as entered in NPPES) on the Massachusetts Board of Registration in Medicine; the Medicare figures below come from public CMS files.
- Name
- Mark Stephan Ostrem
- Credential
- MD
- Primary taxonomy
- Geriatric Medicine (Internal Medicine) Physician 207RG0300X
- License number
- 44501 MA
Self-reported in NPPES; status is on the state search - Practice location
- 54 Miller St, Quincy, MA 02169
- Phone
- (617) 481-3300
- Enumerated
- Oct 6, 2005
- Record last updated
- Jan 15, 2018 (not updated in 8 years: call before relying on the address or phone)
- Fax
- (617) 481-3305
- Medicare enrollment
- Enrolled (PECOS I20041215000212); accepts Medicare assignment
- Medical or professional school
- University Of Minnesota Medical School, 1976
- Entity
- Type 1 · individual
8 nearest geriatric medicine (internal medicine) physician records → All 225 in Massachusetts → Look up another NPI →
Also registered at 54 Miller St
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Heather BuchananMental Health Counselor1134073877
- Brendan CarleyStudent in an Organized Health Care Education/Training Program1255297735
- Samyuktaa Chawla, MSMental Health Counselor1518703628
- Olivia CorneyeaSocial Worker1871412023
- Shaohua Deng, NPNurse Practitioner1174760326
- Melissa DetillioCounselor1265554455
Verify Mark Stephan Ostrem in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMassachusetts Board of Registration in Medicine
Search for license 44501Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
3.9 times the Medicare Part D claims of the average geriatric medicine (internal medicine) physician in 2024
16,508 Medicare Part D claims for 209 beneficiaries, against an average of 4,246 among the 3,116 providers of this specialty who prescribed in Part D. Brand-name drugs were 19% of claims. 203 claims were for opioids.
Most prescribed
- Trazodone Hcl793 claims
- Atorvastatin Calcium716 claims
- Eliquis514 claims
- Gabapentin495 claims
- Baclofen435 claims
- Furosemide428 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
- Pembroke Medical Associates IncPembroke, MA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Mark Stephan Ostrem among 225 geriatric medicine (internal medicine) physician records in Massachusetts
Mark Stephan Ostrem, MD is one of 225 geriatric medicine (internal medicine) physician records with a practice address in Massachusetts. 71% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2005, is newer than 0% of them.
- NPI issued2005 · 0% of these records are older, 86% newer
- In a Medicare fileYes · 71% of these records are
- In the CMS Doctors and Clinicians fileYes · 53% of these records are
- Graduated1976 · median 2000 among the 119 with a school on file
- Record last updated2018 · 63% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RG0300X and a Massachusetts practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Geriatric Medicine (Internal Medicine) Physician providers in Massachusetts
There are 225 geriatric medicine (internal medicine) physician records in Massachusetts.
All 225 in Massachusetts → Every provider in Quincy → Geriatric Medicine (Internal Medicine) Physician nationwide →
The 8 geriatric medicine (internal medicine) physician records with the nearest ZIP codes
- Cynthia Cullinane, M.D.Quincy, MA 021691386645679
- Richard Marquis, M.D.Quincy, MA 021691255321253
- Deborah O'Keefe, M.D.Quincy, MA 021691538159579
- David Barrasso, M.D.Medford, MA 021551467433748
- Saeid Elmi, M.D.Medford, MA 021551023105459
- Michael Cantor, MDBraintree, MA 021841730130212
- Lynne Brodsky, MDChelsea, MA 021501588655419
- Sanja Percac-Lima, MDChelsea, MA 021501508837428
Common questions
What is Mark Stephan Ostrem, MD's NPI number?
Mark Stephan Ostrem, MD's National Provider Identifier (NPI) is 1811985633, issued on Oct 6, 2005. An NPI identifies a provider in billing; it is not a license.
Where is Mark Stephan Ostrem, MD located?
The NPPES record lists a practice address at 54 Miller St, Quincy, MA, 02169. Phone: (617) 481-3300. Providers update this record themselves, so call before visiting.
How can I verify Mark Stephan Ostrem, MD's license?
NPPES lists Massachusetts license number 44501, as entered by the provider. Search the Massachusetts Board of Registration in Medicine at https://findmydoctor.mass.gov/. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Mark Stephan Ostrem, MD prescribe under Medicare Part D?
In 2024, Mark Stephan Ostrem, MD had 16,508 Medicare Part D claims for 209 beneficiaries; the average among geriatric medicine (internal medicine) physician prescribers was 4,246. 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.