Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Michael D Wertheimer, M.D.

Surgical Oncology Physician in Worcester, MA · enumerated 2006.

Data current as of Jul 13, 2026 · sourced from CMS NPPES

National Provider Identifier

1265540975

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Registry record

Entity type Individual (Type 1)

Name Michael D Wertheimer

Credential M.D.

Sex Male

Practice address Umass Memorial Health Care, 119 Belmont Street, Worcester, MA, 01605

Phone (508) 334-5132

Enumeration date Aug 25, 2006

Last updated in NPPES Jul 20, 2015

Taxonomy & licenses

2086X0206X Surgical Oncology Physician Allopathic & Osteopathic Physicians · License 34387 (MA) Primary

MD · Doctor of Medicine: A physician who completed medical school (allopathic medicine), residency training, and state licensure. About the MD credential

What is an NPI number?

A National Provider Identifier (NPI) is a unique 10-digit number that CMS assigns to every U.S. healthcare provider and organization under HIPAA. Type 1 NPIs identify individual providers; Type 2 NPIs identify organizations. The NPI appears on insurance claims, prescriptions, and credentialing paperwork, and never changes, even if the provider moves or changes specialty.

Read the full guide → Validate an NPI →

Frequently asked questions

Where does Michael Wertheimer practice?

The practice location on file with NPPES is in Worcester, MA. Providers can have multiple locations; NPPES lists the primary practice address.

What is the NPI number for Michael Wertheimer?

The National Provider Identifier (NPI) for Michael Wertheimer is 1265540975, a Type 1 (individual) record in the CMS NPPES registry.

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2015-07-20.