Marian Isaak, MD
Internal Medicine Physician · Holyoke, MA
Marian Isaak, MD is an internal medicine physician with a practice address in Holyoke, Massachusetts, and NPI 1083340004, issued on Aug 1, 2022. Check the license (Massachusetts 1024101, as entered in NPPES) on the Massachusetts Board of Registration in Medicine; the Medicare figures below come from public CMS files.
- Name
- Marian Isaak
- Credential
- MD
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- 1024101 MA
Self-reported in NPPES; status is on the state search - Practice location
- 575 Beech St, Holyoke, MA 01040
- Phone
- (413) 534-2500
- Enumerated
- Aug 1, 2022
- Record last updated
- Sep 26, 2025
- Medicare enrollment
- Enrolled (PECOS I20260413000123); accepts Medicare assignment
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 6,825 in Massachusetts → Look up another NPI →
Also registered at 575 Beech St
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Stephanie Adamski, PA-CMedical Physician Assistant1265833768
- Rudegelio Agana, M.D.Anesthesiology Physician1821106873
- Majedah Mahmoud AlfuqaraStudent in an Organized Health Care Education/Training Program1649848003
- Vamseedhar Alla, M.D.Internal Medicine Physician1083646517
- Susan Anti, M.D.Anesthesiology Physician1306837174
- Yazan Batarseh, PHARM.DPharmacist1326995234
Verify Marian Isaak in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMassachusetts Board of Registration in Medicine
Search for license 1024101Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
99% fewer Medicare Part D claims than the average internal medicine physician in 2024
33 Medicare Part D claims for 19 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D.
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
- Western Mass Physician Associates IncHolyoke, MA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Marian Isaak among 6,825 internal medicine physician records in Massachusetts
Marian Isaak, MD is one of 6,825 internal medicine physician records with a practice address in Massachusetts. 75% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2022, is newer than 92% of them.
- NPI issued2022 · 92% of these records are older, 5% newer
- In a Medicare fileYes · 75% of these records are
- In the CMS Doctors and Clinicians fileYes · 60% of these records are
- Graduated2021 · median 2004 among the 4,103 with a school on file
- Record last updated2025 · 64% 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 Massachusetts practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
31 internal medicine physician records list a practice address in Holyoke
They are 31 of the 1,961 NPPES records with a practice address in Holyoke, and 6,825 internal medicine physician records in Massachusetts.
All 6,825 in Massachusetts → Every provider in Holyoke → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Purnima Adlakha, M.D.Holyoke, MA 010401487601175
- Tazeen Aleem, MDHolyoke, MA 010401760466494
- Vamseedhar Alla, M.D.Holyoke, MA 010401083646517
- Kenneth Aquilino, MDHolyoke, MA 010401770583668
- Vanessa Begolli, M.D.Holyoke, MA 010401770553562
- Ana Maria Castrillon, MDHolyoke, MA 010401932174570
- Alejandro Esparza-Perez, M.D.Holyoke, MA 010401124098595
- Thomas Judd, MDHolyoke, MA 010401780788802
Common questions
What is Marian Isaak, MD's NPI number?
Marian Isaak, MD's National Provider Identifier (NPI) is 1083340004, issued on Aug 1, 2022. An NPI identifies a provider in billing; it is not a license.
Where is Marian Isaak, MD located?
The NPPES record lists a practice address at 575 Beech St, Holyoke, MA, 01040. Phone: (413) 534-2500. Providers update this record themselves, so call before visiting.
How can I verify Marian Isaak, MD's license?
NPPES lists Massachusetts license number 1024101, 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 Marian Isaak, MD prescribe under Medicare Part D?
In 2024, Marian Isaak, MD had 33 Medicare Part D claims for 19 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.