William Seng Tan, D.O.
Family Medicine Physician · Olympia Fields, IL
William Seng Tan, D.O. is a family medicine physician with a practice address in Olympia Fields, Illinois, and NPI 1891112306, issued on Mar 21, 2014. Check the license (Illinois 036144064, as entered in NPPES) on the Illinois Department of Financial and Professional Regulation; the Medicare figures below come from public CMS files.
- Name
- William Seng Tan
- Credential
- D.O.
- Primary taxonomy
- Family Medicine Physician 207Q00000X
- License number
- 036144064 IL
Self-reported in NPPES; status is on the state search - Practice location
- 20060 Governors Dr Ste 204, Olympia Fields, IL 60461
- Phone
- (708) 283-8300
- Enumerated
- Mar 21, 2014
- Record last updated
- Dec 25, 2021 (not updated in 5 years: call before relying on the address or phone)
- Fax
- (708) 283-9245
- Medicare enrollment
- Enrolled (PECOS I20170919004165); accepts Medicare assignment
- Medical or professional school
- Nova Southeastern College Of Osteo Medicine, 2013
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest family medicine physician records → All 6,215 in Illinois → Look up another NPI →
Also registered at 20060 Governors Dr Ste 204
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Savio Manatt, M.D.Internal Medicine Physician1063585032
Verify William Seng Tan 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 036144064Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
2.2 times the Medicare Part D claims of the average family medicine physician in 2024
7,881 Medicare Part D claims for 725 beneficiaries, against an average of 3,544 among the 117,163 providers of this specialty who prescribed in Part D. Brand-name drugs were 10% of claims. 506 claims were for opioids.
Most prescribed
- Atorvastatin Calcium479 claims
- Amlodipine Besylate293 claims
- Losartan Potassium248 claims
- Hydrocodone-Acetaminophen232 claims
- Metoprolol Succinate194 claims
- Hydrochlorothiazide192 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.
Industry payments in 2024: $22.88
1 payment: food and beverage; the largest payer was Novo Nordisk 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.
William Seng Tan among 6,215 family medicine physician records in Illinois
William Seng Tan, 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 2014, is newer than 66% of them.
- NPI issued2014 · 66% of these records are older, 32% newer
- In a Medicare fileYes · 78% of these records are
- In the CMS Doctors and Clinicians fileYes · 60% of these records are
- Graduated2013 · median 2006 among the 3,714 with a school on file
- Record last updated2021 · 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).
20 family medicine physician records list a practice address in Olympia Fields
They are 20 of the 684 NPPES records with a practice address in Olympia Fields, and 6,215 family medicine physician records in Illinois.
All 6,215 in Illinois → Every provider in Olympia Fields → Family Medicine Physician nationwide →
The 8 family medicine physician records with the nearest ZIP codes
- Mirza Khalid Baig, MDOlympia Fields, IL 604611194776377
- Charles Barron, MDOlympia Fields, IL 604611457433039
- Kathryn Burke, DOOlympia Fields, IL 604611316943848
- William Imlach, D.O.Olympia Fields, IL 604611699850610
- Allison Martin, M.D.Olympia Fields, IL 604611114033669
- Howard Mc Nair, M.D.Olympia Fields, IL 604611609808518
- James McGarry, M.D.Olympia Fields, IL 604611710945852
- Rita Oganwu, MDOlympia Fields, IL 604611962452193
Common questions
What is William Seng Tan, D.O.'s NPI number?
William Seng Tan, D.O.'s National Provider Identifier (NPI) is 1891112306, issued on Mar 21, 2014. An NPI identifies a provider in billing; it is not a license.
Where is William Seng Tan, D.O. located?
The NPPES record lists a practice address at 20060 Governors Dr Ste 204, Olympia Fields, IL, 60461. Phone: (708) 283-8300. Providers update this record themselves, so call before visiting.
How can I verify William Seng Tan, D.O.'s license?
NPPES lists Illinois license number 036144064, 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 Seng Tan, D.O. prescribe under Medicare Part D?
In 2024, William Seng Tan, D.O. had 7,881 Medicare Part D claims for 725 beneficiaries; the average among family medicine physician prescribers was 3,544. 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.