Olwen M. Hahn, M.D.
Hematology & Oncology Physician · Chicago, IL
Olwen M. Hahn, M.D. is a hematology & oncology physician with a practice address in Chicago, Illinois, and NPI 1992823611, issued on Mar 27, 2007. Check the license on the Illinois Department of Financial and Professional Regulation; the Medicare figures below come from public CMS files.
- Name
- Olwen M. Hahn
- Credential
- M.D.
- Primary taxonomy
- Hematology & Oncology Physician 207RH0003X
- Practice location
- 5841 S Maryland Ave, Chicago, IL 60637
- Phone
- (773) 702-5381
- Enumerated
- Mar 27, 2007
- Record last updated
- Jul 8, 2007 (not updated in 19 years: call before relying on the address or phone)
- Fax
- (773) 702-3163
- Medicare enrollment
- Enrolled (PECOS I20070713000357); accepts Medicare assignment
- Medical or professional school
- Emory University School Of Medicine, 2001
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest hematology & oncology physician records → All 666 in Illinois → Look up another NPI →
Also registered at 5841 S Maryland Ave
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify Olwen M. Hahn in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersIllinois Department of Financial and Professional RegulationCheck the board
- 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
55% fewer Medicare Part D claims than the average hematology & oncology physician in 2024
394 Medicare Part D claims for 86 beneficiaries, against an average of 877 among the 10,784 providers of this specialty who prescribed in Part D. Brand-name drugs were 24% of claims. 18 claims were for opioids.
Most prescribed
- Anastrozole133 claims
- Exemestane26 claims
- Kisqali24 claims
- Tamoxifen Citrate24 claims
- Letrozole20 claims
- Verzenio17 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.
The MIPS final score for 2023 (Medicare payment program): 97.7 of 100
The Merit-based Incentive Payment System score is reported for this clinician. Four categories are weighted into the final score; the average among 454,083 clinicians with a measured score was 83.5.
Source: CMS Quality Payment Program, MIPS performance year 2023; category weights for 2023 (qpp.cms.gov).
Industry payments in 2024: $1,736.99
11 payments; by number, the most common kind was food and beverage; the largest payer was AstraZeneca UK Limited. The 8,560 providers of this specialty with any payment received $7,481.41 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.
2 hospitals and group practices
- The University OF Chicago Medical CenterChicago, IL · Acute Care Hospitals4 of 5 stars
- University OF ChicagoChicago, IL
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through); hospitals matched to CMS Hospital General Information (Care Compare) (data.cms.gov). Star ratings are CMS hospital ratings, not ratings of this provider.
Olwen M. Hahn among 666 hematology & oncology physician records in Illinois
Olwen M. Hahn, M.D. is one of 666 hematology & oncology physician records with a practice address in Illinois. 84% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2007, is newer than 43% of them.
- NPI issued2007 · 43% of these records are older, 48% newer
- In a Medicare fileYes · 84% of these records are
- In the CMS Doctors and Clinicians fileYes · 69% of these records are
- Graduated2001 · median 2003 among the 461 with a school on file
- Record last updated2007 · 49% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RH0003X and a Illinois practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Hematology & Oncology Physician providers in Illinois
There are 666 hematology & oncology physician records in Illinois.
All 666 in Illinois → Every provider in Chicago → Hematology & Oncology Physician nationwide →
The 8 hematology & oncology physician records with the nearest ZIP codes
- Julia Ashenhurst, M.D.Chicago, IL 606371336225358
- Christopher DaughertyChicago, IL 606371063574523
- Gini FlemingChicago, IL 606371407918964
- Thomas GajewskiChicago, IL 606371194888610
- Philip HoffmanChicago, IL 606371700949229
- Richard LarsonChicago, IL 606371114089661
- Rita NandaChicago, IL 606371568524015
- Sunil NarulaChicago, IL 606371861428583
Common questions
What is Olwen M. Hahn, M.D.'s NPI number?
Olwen M. Hahn, M.D.'s National Provider Identifier (NPI) is 1992823611, issued on Mar 27, 2007. An NPI identifies a provider in billing; it is not a license.
Where is Olwen M. Hahn, M.D. located?
The NPPES record lists a practice address at 5841 S Maryland Ave, Chicago, IL, 60637. Phone: (773) 702-5381. Providers update this record themselves, so call before visiting.
How can I verify Olwen M. Hahn, M.D.'s license?
Search the Illinois Department of Financial and Professional Regulation at https://idfpr.illinois.gov/checklicense.html. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Olwen M. Hahn, M.D. prescribe under Medicare Part D?
In 2024, Olwen M. Hahn, M.D. had 394 Medicare Part D claims for 86 beneficiaries; the average among hematology & oncology physician prescribers was 877. Part D covers Medicare prescriptions only.
What is Olwen M. Hahn, M.D.'s MIPS final score?
The 2023 MIPS final score is 97.7 of 100. The average among 454,083 clinicians with a measured score was 83.5.
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.