Thomas Claudio Guillermo Tsai, MD
Internal Medicine Physician · Framingham, MA
Thomas Claudio Guillermo Tsai, MD is an internal medicine physician with a practice address in Framingham, Massachusetts, and NPI 1548963945, issued on Mar 24, 2023. Check the license (Massachusetts 3014722, as entered in NPPES) on the Massachusetts Board of Registration in Medicine; the Medicare figures below come from public CMS files.
- Name
- Thomas Claudio Guillermo Tsai
- Credential
- MD
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- 3014722 MA
Self-reported in NPPES; status is on the state search - Practice location
- 115 Lincoln St, Framingham, MA 01702
- Phone
- (508) 383-1000
- Enumerated
- Mar 24, 2023
- Record last updated
- Jun 29, 2023
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 6,825 in Massachusetts → Look up another NPI →
Also registered at 115 Lincoln St
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify Thomas Claudio Guillermo Tsai in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMassachusetts Board of Registration in Medicine
Search for license 3014722Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
92% fewer Medicare Part D claims than the average internal medicine physician in 2024
257 Medicare Part D claims for 64 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 19% of claims.
Most prescribed
- Atenolol14 claims
- Atorvastatin Calcium12 claims
- Mounjaro11 claims
- Pantoprazole Sodium11 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: $176.46
5 payments; by number, the most common kind was food and beverage; the largest payer was Actelion Pharmaceuticals US, Inc. 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.
Thomas Claudio Guillermo Tsai among 6,825 internal medicine physician records in Massachusetts
Thomas Claudio Guillermo Tsai, MD is one of 6,825 internal medicine physician records with a practice address in Massachusetts. 75% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2023, is newer than 95% of them.
- NPI issued2023 · 95% of these records are older, 3% newer
- In a Medicare fileYes · 75% of these records are
- In the CMS Doctors and Clinicians fileNo · 60% of these records are
- Record last updated2023 · 64% 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 Massachusetts practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
93 internal medicine physician records list a practice address in Framingham
They are 93 of the 3,069 NPPES records with a practice address in Framingham, and 6,825 internal medicine physician records in Massachusetts.
All 6,825 in Massachusetts → Every provider in Framingham → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Michael Bean, MDFramingham, MA 017021447266408
- Joseph Harrington, MDFramingham, MA 017021346204419
- Stephen Hoffmann, MDFramingham, MA 017021295736494
- Li-Ming Hu, MDFramingham, MA 017021811952930
- Shahnaz Montague, M.D.Framingham, MA 017021457308249
- Timothy Odonnell, MDFramingham, MA 017021346206091
- Irma Rasmussen, MDFramingham, MA 017021144287236
- Eduardo Ribeiro, MDFramingham, MA 017021649256751
Common questions
What is Thomas Claudio Guillermo Tsai, MD's NPI number?
Thomas Claudio Guillermo Tsai, MD's National Provider Identifier (NPI) is 1548963945, issued on Mar 24, 2023. An NPI identifies a provider in billing; it is not a license.
Where is Thomas Claudio Guillermo Tsai, MD located?
The NPPES record lists a practice address at 115 Lincoln St, Framingham, MA, 01702. Phone: (508) 383-1000. Providers update this record themselves, so call before visiting.
How can I verify Thomas Claudio Guillermo Tsai, MD's license?
NPPES lists Massachusetts license number 3014722, as entered by the provider. Search the Massachusetts Board of Registration in Medicine at https://findmydoctor.mass.gov/. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Thomas Claudio Guillermo Tsai, MD prescribe under Medicare Part D?
In 2024, Thomas Claudio Guillermo Tsai, MD had 257 Medicare Part D claims for 64 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.