Type 2 · Organization ✓ Active NPI ✓ Valid NPI checksum

Calvin L. Day, Jr., M.D., P.A.

Dermatology Physician in San Antonio, TX · enumerated 2005 · authorized official Calvin Day, President.

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

National Provider Identifier

1861487167

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Registry record

Entity type Organization (Type 2)

Legal business name Calvin L. Day, Jr., M.D., P.A.

Practice address 7711 Louis Pasteur Dr Suite 104, San Antonio, TX, 78229

Phone (210) 615-8345

Enumeration date Sep 13, 2005

Last updated in NPPES Feb 19, 2008

Taxonomy & classification

207N00000X Dermatology Physician Allopathic & Osteopathic Physicians · License G1883 (TX) Primary

Authorized official

Name Calvin Day

Title President

Phone (210) 615-8345

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

How current is this record?

Data comes from the CMS NPPES public dissemination file; this record was last updated in NPPES on 2008-02-19. Verify at npiregistry.cms.hhs.gov.

Where is Calvin L. Day, Jr., M.D., P.A. located?

The practice location on file with NPPES is in San Antonio, TX.

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2008-02-19.