Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Mr. Michael Steven Santillan, PA-C, CAQ-PSYCH

Medical Physician Assistant in Mission Viejo, CA · enumerated 2022.

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

National Provider Identifier

1861139628

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Registry record

Entity type Individual (Type 1)

Name Mr. Michael Steven Santillan

Credential PA-C, CAQ-PSYCH

Sex Male

Practice address 26024 Acero, Mission Viejo, CA, 92691

Phone (714) 545-5550

Fax (949) 609-0374

Enumeration date May 13, 2022

Last updated in NPPES Sep 30, 2025

Taxonomy & licenses

364SP0808X Psychiatric/Mental Health Clinical Nurse Specialist Physician Assistants & Advanced Practice Nursing Providers · License PA61412 (CA) Secondary

363AM0700X Medical Physician Assistant Physician Assistants & Advanced Practice Nursing Providers · License PA61412 (CA) Primary

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

How do I verify Michael Santillan's NPI record?

Cross-check NPI 1861139628 against the official CMS registry at npiregistry.cms.hhs.gov. This page mirrors the same public NPPES data with a monthly snapshot.

Is NPI 1861139628 active?

Yes, as of the latest NPPES snapshot, NPI 1861139628 is active (record last updated 2025-09-30).

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2025-09-30.