Thomas J. Williamson, MD
Internal Medicine Physician · Houston, TX
Thomas J. Williamson, MD is an internal medicine physician with a practice address in Houston, Texas, and NPI 1013003201, issued on Oct 5, 2006. Check the license (Texas L0701, as entered in NPPES) on the Texas Medical Board; the Medicare figures below come from public CMS files.
- Name
- Thomas J. Williamson
- Credential
- MD
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- L0701 TX
Self-reported in NPPES; status is on the state search - Practice location
- 560 Meyerland Plaza Mall, Houston, TX 77096
- Phone
- (713) 442-3222
- Enumerated
- Oct 5, 2006
- Record last updated
- Jun 23, 2021 (not updated in 5 years: call before relying on the address or phone)
- Medicaid ID
- 143528103 TX
- Medicare enrollment
- Enrolled (PECOS I20031205000087); accepts Medicare assignment
- Medical or professional school
- Ohio State University College Of Medicine, 1997
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 9,175 in Texas → Look up another NPI →
Also registered at 560 Meyerland Plaza Mall
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Evan Abdullah, MDInternal Medicine Physician1982286696
- Rawan Abu-ElheigaPharmacist1043693732
- Amaka Akinade, NPNurse Practitioner1942781257
- Claudette Alvarez-PeschkePharmacist1972985570
- Jenny Bao, M.D.Family Medicine Physician1295029882
- Lee Bar-Eli, MDFamily Medicine Physician1609006543
Verify Thomas J. Williamson in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersTexas Medical Board
Search for license L0701Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
3.1 times the Medicare Part D claims of the average internal medicine physician in 2024
9,867 Medicare Part D claims for 701 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 10% of claims. 124 claims were for opioids.
Most prescribed
- Atorvastatin Calcium630 claims
- Amlodipine Besylate420 claims
- Levothyroxine Sodium301 claims
- Lisinopril295 claims
- Omeprazole283 claims
- Tamsulosin Hcl270 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: $15.61
1 payment: food and beverage; the largest payer was AstraZeneca Pharmaceuticals LP. The 50,334 providers of this specialty with any payment received $1,303.06 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
- Kelsey-Seybold Medical Group, PLLCHouston, TX
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Thomas J. Williamson among 9,175 internal medicine physician records in Texas
Thomas J. Williamson, MD is one of 9,175 internal medicine physician records with a practice address in Texas. 82% 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 · 82% of these records are
- In the CMS Doctors and Clinicians fileYes · 66% of these records are
- Graduated1997 · median 2004 among the 6,088 with a school on file
- Record last updated2021 · 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 207R00000X and a Texas practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
1,488 internal medicine physician records list a practice address in Houston
They are 1,488 of the 61,221 NPPES records with a practice address in Houston, and 9,175 internal medicine physician records in Texas.
All 9,175 in Texas → Every provider in Houston → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Evan Abdullah, MDHouston, TX 770961982286696
- John Anigbogu, M.D.Houston, TX 770961497718688
- Anwesha Chaudhuri, M.D.Houston, TX 770961659018844
- Olethia Chisolm, MDHouston, TX 770961679504120
- Paul Gustafson, M.D.Houston, TX 770961265557110
- Russell Pacquette, MDHouston, TX 770961447568597
- Carlos Rivera, MDHouston, TX 770961851488407
- Iftikhar Sarwar, MDHouston, TX 770961225117500
Common questions
What is Thomas J. Williamson, MD's NPI number?
Thomas J. Williamson, MD's National Provider Identifier (NPI) is 1013003201, issued on Oct 5, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Thomas J. Williamson, MD located?
The NPPES record lists a practice address at 560 Meyerland Plaza Mall, Houston, TX, 77096. Phone: (713) 442-3222. Providers update this record themselves, so call before visiting.
How can I verify Thomas J. Williamson, MD's license?
NPPES lists Texas license number L0701, as entered by the provider. Search the Texas Medical Board at https://profile.tmb.state.tx.us/Search.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Thomas J. Williamson, MD prescribe under Medicare Part D?
In 2024, Thomas J. Williamson, MD had 9,867 Medicare Part D claims for 701 beneficiaries; the average among internal medicine physician prescribers was 3,176. 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.