Natalia Baj-Osiewicz, MD
Internal Medicine Physician · Flint, MI
Natalia Baj-Osiewicz, MD is an internal medicine physician with a practice address in Flint, Michigan, and NPI 1619405123, issued on May 28, 2017. Check the license (Michigan 4301507488, as entered in NPPES) on the Michigan Board of Medicine (LARA); the Medicare figures below come from public CMS files.
- Name
- Natalia Baj-Osiewicz
- Credential
- MD
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- 4301507488 MI
Self-reported in NPPES; status is on the state search - Practice location
- 420 S Saginaw St, Flint, MI 48502
- Phone
- (810) 232-3522
- Enumerated
- May 28, 2017
- Record last updated
- Jun 23, 2022
- Medicare enrollment
- Enrolled (PECOS I20220627003063); accepts Medicare assignment
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 5,735 in Michigan → Look up another NPI →
Also registered at 420 S Saginaw St
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Kelcie Crandall, NPFamily Nurse Practitioner1467094755
- Jacky Duong, DOInternal Medicine Physician1780693671
- Susan Enright, DOInternal Medicine Physician1912948712
- Kelsee Rotondo, DOInternal Medicine Physician1629692140
- Bhavna Vaniawala, MDPediatrics Physician1639300692
- Sheel VaniawalaInternal Medicine Physician1225732993
Verify Natalia Baj-Osiewicz in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMichigan Board of Medicine (LARA)
Search for license 4301507488Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
89% fewer Medicare Part D claims than the average internal medicine physician in 2024
345 Medicare Part D claims for 59 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 15% of claims. 17 claims were for opioids.
Most prescribed
- Atorvastatin Calcium18 claims
- Amlodipine Besylate15 claims
- Metformin Hcl15 claims
- Omeprazole15 claims
- Duloxetine Hcl11 claims
- Venlafaxine Hcl Er11 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
- Henry Ford Health Genesys HospitalFlint, MI
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Natalia Baj-Osiewicz among 5,735 internal medicine physician records in Michigan
Natalia Baj-Osiewicz, MD is one of 5,735 internal medicine physician records with a practice address in Michigan. 79% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2017, is newer than 71% of them.
- NPI issued2017 · 71% of these records are older, 26% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileYes · 62% of these records are
- Graduated2013 · median 2006 among the 3,564 with a school on file
- Record last updated2022 · 54% 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 Michigan practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
187 internal medicine physician records list a practice address in Flint
They are 187 of the 6,073 NPPES records with a practice address in Flint, and 5,735 internal medicine physician records in Michigan.
All 5,735 in Michigan → Every provider in Flint → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Jacky Duong, DOFlint, MI 485021780693671
- Susan Enright, DOFlint, MI 485021912948712
- Kelsee Rotondo, DOFlint, MI 485021629692140
- Sheel VaniawalaFlint, MI 485021225732993
- Himabindu Yarlagadda, MDFlint, MI 485021881609345
- Khalid Ahmed, MDFlint, MI 485031619965175
- Hernan Gomez, M.D.Flint, MI 485031154419562
- Franz Jaggi, D.O.Flint, MI 485031548358666
Common questions
What is Natalia Baj-Osiewicz, MD's NPI number?
Natalia Baj-Osiewicz, MD's National Provider Identifier (NPI) is 1619405123, issued on May 28, 2017. An NPI identifies a provider in billing; it is not a license.
Where is Natalia Baj-Osiewicz, MD located?
The NPPES record lists a practice address at 420 S Saginaw St, Flint, MI, 48502. Phone: (810) 232-3522. Providers update this record themselves, so call before visiting.
How can I verify Natalia Baj-Osiewicz, MD's license?
NPPES lists Michigan license number 4301507488, as entered by the provider. Search the Michigan Board of Medicine (LARA) at https://aca-prod.accela.com/MILARA/GeneralProperty/PropertyLookUp.aspx?isLicensee=Y&TabName=APO. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Natalia Baj-Osiewicz, MD prescribe under Medicare Part D?
In 2024, Natalia Baj-Osiewicz, MD had 345 Medicare Part D claims for 59 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.