William Simon Markey, MD
Gastroenterology Physician · Chicago, IL
William Simon Markey, MD is a gastroenterology physician with a practice address in Chicago, Illinois, and NPI 1033204706, issued on Oct 4, 2006. Check the license (Illinois 36046023, as entered in NPPES) on the Illinois Department of Financial and Professional Regulation; the Medicare figures below come from public CMS files.
- Name
- William Simon Markey
- Credential
- MD
- Primary taxonomy
- Gastroenterology Physician 207RG0100X
- License number
- 36046023 IL
Self-reported in NPPES; status is on the state search - Practice location
- 3000 N Halsted St Ste 506, Chicago, IL 60657
- Phone
- (312) 944-1247
- Enumerated
- Oct 4, 2006
- Record last updated
- May 18, 2009 (not updated in 17 years: call before relying on the address or phone)
- Fax
- (312) 944-2188
- Medicaid ID
- 036046023 IL
- Entity
- Type 1 · individual
8 nearest gastroenterology physician records → All 887 in Illinois → Look up another NPI →
Verify William Simon Markey 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 36046023Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
95% fewer Medicare Part D claims than the average gastroenterology physician in 2024
39 Medicare Part D claims, against an average of 811 among the 16,445 providers of this specialty who prescribed in Part D. Brand-name drugs were 0% of 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.
William Simon Markey among 887 gastroenterology physician records in Illinois
William Simon Markey, MD is one of 887 gastroenterology physician records with a practice address in Illinois. 85% 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, 52% newer
- In a Medicare fileYes · 85% of these records are
- In the CMS Doctors and Clinicians fileNo · 72% of these records are
- Record last updated2009 · 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 207RG0100X and a Illinois practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Gastroenterology Physician providers in Illinois
There are 887 gastroenterology physician records in Illinois.
All 887 in Illinois → Every provider in Chicago → Gastroenterology Physician nationwide →
The 8 gastroenterology physician records with the nearest ZIP codes
- Andrew Albert, MDChicago, IL 606571659413656
- Carl Atallah, DOChicago, IL 606571922269190
- Manish Dhamija, M.D.Chicago, IL 606571699977413
- Michael Flicker, M.D.Chicago, IL 606571730375627
- Keikhosrow Ghazanfari, MDChicago, IL 606571831188747
- Lawrence Gluskin, MDChicago, IL 606571235109711
- Frank Konicek, MDChicago, IL 606571619966447
- Krutika Lakhoo, MDChicago, IL 606571407199458
Common questions
What is William Simon Markey, MD's NPI number?
William Simon Markey, MD's National Provider Identifier (NPI) is 1033204706, issued on Oct 4, 2006. An NPI identifies a provider in billing; it is not a license.
Where is William Simon Markey, MD located?
The NPPES record lists a practice address at 3000 N Halsted St Ste 506, Chicago, IL, 60657. Phone: (312) 944-1247. Providers update this record themselves, so call before visiting.
How can I verify William Simon Markey, MD's license?
NPPES lists Illinois license number 36046023, 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 Simon Markey, MD prescribe under Medicare Part D?
In 2024, William Simon Markey, MD had 39 Medicare Part D claims; the average among gastroenterology physician prescribers was 811. 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.