Type 2 · Organization ✓ Active NPI ✓ Valid NPI checksum

Alfonso Tan MD PC

Internal Medicine Physician in Sayville, NY · enumerated 2006 · authorized official Alfonso Tan, President.

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

National Provider Identifier

1548348758

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Registry record

Entity type Organization (Type 2)

Legal business name Alfonso Tan MD PC

Practice address 297 W Main St, Sayville, NY, 11782

Phone (631) 589-2323

Fax (631) 589-9069

Enumeration date Nov 2, 2006

Last updated in NPPES Nov 2, 2007

Taxonomy & classification

207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License 115465 (NY) Primary

Authorized official

Name Alfonso Tan

Title President

Phone (631) 589-2323

Other identifiers

Identifier	Type	State	Issuer
00213052	Medicaid	NY	-

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 is Alfonso Tan MD PC located?

The practice location on file with NPPES is in Sayville, NY.

How current is this record?

Data comes from the CMS NPPES public dissemination file; this record was last updated in NPPES on 2007-11-02. Verify at npiregistry.cms.hhs.gov.

Providers at this address

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Alfonso Tan Internal Medicine Physician · Sayville, NY NPI 1588689566

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2007-11-02.