William S. O'Reilly, M.D.
Hematology & Oncology Physician · Palos Heights, IL
William S. O'Reilly, M.D. is a hematology & oncology physician with a practice address in Palos Heights, Illinois, and NPI 1437124625, issued on Feb 21, 2006. Check the license (Illinois 036053590, as entered in NPPES) on the Illinois Department of Financial and Professional Regulation; the Medicare figures below come from public CMS files.
- Name
- William S. O'Reilly
- Credential
- M.D.
- Primary taxonomy
- Hematology & Oncology Physician 207RH0003X
- License number
- 036053590 IL
Self-reported in NPPES; status is on the state search - Practice location
- 12150 S Harlem Ave, Palos Heights, IL 60463
- Phone
- (708) 361-4778
- Enumerated
- Feb 21, 2006
- Record last updated
- Mar 2, 2010 (not updated in 16 years: call before relying on the address or phone)
- Entity
- Type 1 · individual
8 nearest hematology & oncology physician records → All 666 in Illinois → Look up another NPI →
Also registered at 12150 S Harlem Ave
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Patricia Kehoe, NPNurse Practitioner1821735150
- William Kosmala, M.D.Gastroenterology Physician1760442511
- Daniel Oreilly, M.D.Gastroenterology Physician1457325987
Verify William S. O'Reilly in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersIllinois Department of Financial and Professional Regulation
Search for license 036053590Check 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 hematology & oncology physician in 2024
21 Medicare Part D claims, against an average of 877 among the 10,784 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.
William S. O'Reilly among 666 hematology & oncology physician records in Illinois
William S. O'Reilly, 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 2006, is newer than 15% of them.
- NPI issued2006 · 15% of these records are older, 57% newer
- In a Medicare fileYes · 84% of these records are
- In the CMS Doctors and Clinicians fileNo · 69% of these records are
- Record last updated2010 · 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 Palos Heights → Hematology & Oncology Physician nationwide →
The 8 hematology & oncology physician records with the nearest ZIP codes
- Yaseen Alkaddoumi, M.D.Orland Park, IL 604621548668148
- Amani ErraOrland Park, IL 604621033526165
- Asad Javed, M.D.Orland Park, IL 604621427339928
- Yazan Numan, MDOrland Park, IL 604621801243738
- Sylvia Falls, MDOrland Park, IL 604671528231750
- Jayanthi Ramadurai, MDBurbank, IL 604591639196330
- Riaz Elahi, MDOak Lawn, IL 604531356421325
- Rami Haddad, MDOak Lawn, IL 604531710072624
Common questions
What is William S. O'Reilly, M.D.'s NPI number?
William S. O'Reilly, M.D.'s National Provider Identifier (NPI) is 1437124625, issued on Feb 21, 2006. An NPI identifies a provider in billing; it is not a license.
Where is William S. O'Reilly, M.D. located?
The NPPES record lists a practice address at 12150 S Harlem Ave, Palos Heights, IL, 60463. Phone: (708) 361-4778. Providers update this record themselves, so call before visiting.
How can I verify William S. O'Reilly, M.D.'s license?
NPPES lists Illinois license number 036053590, as entered by the provider. 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 William S. O'Reilly, M.D. prescribe under Medicare Part D?
In 2024, William S. O'Reilly, M.D. had 21 Medicare Part D claims; the average among hematology & oncology physician prescribers was 877. 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.