William J. Ennis, D.O.
Family Medicine Physician · Chicago, IL
William J. Ennis, D.O. is a family medicine physician with a practice address in Chicago, Illinois, and NPI 1649225988, issued on May 24, 2006. Check the license (Illinois 036084083, as entered in NPPES) on the Illinois Department of Financial and Professional Regulation; the Medicare figures below come from public CMS files.
- Name
- William J. Ennis
- Credential
- D.O.
- Primary taxonomy
- Family Medicine Physician 207Q00000X
- License number
- 036084083 IL
Self-reported in NPPES; status is on the state search - Practice location
- 1801 W Taylor St, Chicago, IL 60612
- Phone
- (312) 996-3253
- Enumerated
- May 24, 2006
- Record last updated
- Jun 16, 2018 (not updated in 8 years: call before relying on the address or phone)
- Fax
- (312) 413-0495
- Medicaid ID
- 036084083 IL
- Medicare enrollment
- Enrolled (PECOS I20040726000220); accepts Medicare assignment
- Medical or professional school
- New York College Of Osteo Medicine Of New York Institute Of Technology, 1985
- Entity
- Type 1 · individual
8 nearest family medicine physician records → All 6,215 in Illinois → Look up another NPI →
Also registered at 1801 W Taylor St
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify William J. Ennis 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 036084083Check 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 family medicine physician in 2024
84 Medicare Part D claims for 26 beneficiaries, against an average of 3,544 among the 117,163 providers of this specialty who prescribed in Part D. Brand-name drugs were 0% of claims.
Most prescribed
- Pentoxifylline38 claims
- Doxycycline Monohydrate14 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 practice group's MIPS final score for 2023 (Medicare payment program): 87.1 of 100
The Merit-based Incentive Payment System score is reported for the practice group, not for one clinician alone. 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, group reporting; category weights for 2023 (qpp.cms.gov).
Industry payments in 2024: $27.68
1 payment: food and beverage; the largest payer was RedDress USA, Inc. The 55,478 providers of this specialty with any payment received $902.55 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.
Bills Medicare through one group practice
- The Board OF Trustees OF The University OF IllinoisChicago, IL
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
William J. Ennis among 6,215 family medicine physician records in Illinois
William J. Ennis, D.O. is one of 6,215 family medicine physician records with a practice address in Illinois. 78% 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 9% of them.
- NPI issued2006 · 9% of these records are older, 59% newer
- In a Medicare fileYes · 78% of these records are
- In the CMS Doctors and Clinicians fileYes · 60% of these records are
- Graduated1985 · median 2006 among the 3,714 with a school on file
- Record last updated2018 · 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 207Q00000X and a Illinois practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
1,593 family medicine physician records list a practice address in Chicago
They are 1,593 of the 63,379 NPPES records with a practice address in Chicago, and 6,215 family medicine physician records in Illinois.
All 6,215 in Illinois → Every provider in Chicago → Family Medicine Physician nationwide →
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- David FreedmanChicago, IL 606121568573699
- Samuel Grief, M.D.Chicago, IL 606121821101007
- Tai Tan HuynhChicago, IL 606121801907902
Common questions
What is William J. Ennis, D.O.'s NPI number?
William J. Ennis, D.O.'s National Provider Identifier (NPI) is 1649225988, issued on May 24, 2006. An NPI identifies a provider in billing; it is not a license.
Where is William J. Ennis, D.O. located?
The NPPES record lists a practice address at 1801 W Taylor St, Chicago, IL, 60612. Phone: (312) 996-3253. Providers update this record themselves, so call before visiting.
How can I verify William J. Ennis, D.O.'s license?
NPPES lists Illinois license number 036084083, 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 J. Ennis, D.O. prescribe under Medicare Part D?
In 2024, William J. Ennis, D.O. had 84 Medicare Part D claims for 26 beneficiaries; the average among family medicine physician prescribers was 3,544. Part D covers Medicare prescriptions only.
What is William J. Ennis, D.O.'s MIPS final score?
The 2023 MIPS final score is 87.1 of 100, reported for the practice group. 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.