Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum Sole proprietor

Michael Willen, M.D.

Hematology & Oncology Physician in Clifton Park, NY · enumerated 2005 · practices at Albany Medical College.

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

National Provider Identifier

1912994849

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Registry record

Entity type Individual (Type 1)

Name Michael Willen

Credential M.D.

Sex Male

Practice address Clifton Park, NY, 12065

Phone (518) 831-4434

Fax (518) 831-4435

Enumeration date Oct 5, 2005

Last updated in NPPES Mar 20, 2019

Street address withheld: NPPES sole-proprietor addresses can be home addresses. See our data policy.

Taxonomy & licenses

207RH0003X Hematology & Oncology Physician Allopathic & Osteopathic Physicians · License 131246 (NY) 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.

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Frequently asked questions

Where does Michael Willen practice?

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

What is the NPI number for Michael Willen?

The National Provider Identifier (NPI) for Michael Willen is 1912994849, a Type 1 (individual) record in the CMS NPPES registry.

Other providers at this practice address

Browse all →

Justin Juliano Radiation Oncology Physician · Clifton Park, NY NPI 1841484839 Michael Masterson Oncology Pharmacist · Halfmoon, NY NPI 1114105723 Patricia Stott Adult Health Nurse Practitioner · Clifton Park, NY NPI 1912269861 Adriana Lisinschi Hematology & Oncology Physician · Halfmoon, NY NPI 1013331735 Albany Medical College General Practice Physician · Halfmoon, NY NPI 1871978429 Catherine Mcavoy-Pindar Clinical Social Worker · Clifton Park, NY NPI 1952026817

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2019-03-20.