Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Guillermo Acero, MD

Anatomic Pathology & Clinical Pathology Physician in Ojai, CA · enumerated 2006 · practices at Ojai Valley Emergency Physicians Medical Group Inc.

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

National Provider Identifier

1629144373

Verified

See something wrong? Report a correction

Registry record

Entity type Individual (Type 1)

Name Guillermo Acero

Credential MD

Sex Male

Practice address 1306 Maricopa Highway, Ojai Valley Community Hospital, Ojai, CA, 93023

Phone (805) 646-1401

Fax (805) 646-0431

Enumeration date Nov 27, 2006

Last updated in NPPES Mar 7, 2023

Taxonomy & licenses

207ZP0102X Anatomic Pathology & Clinical Pathology Physician Allopathic & Osteopathic Physicians · License A26498 (CA) Primary

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

Other identifiers

Identifier	Type	State	Issuer
A26498	Other	CA	MEDICAL BOARD OF CA
00A264981	Medicaid	CA	-

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

Is NPI 1629144373 active?

Yes, as of the latest NPPES snapshot, NPI 1629144373 is active (record last updated 2023-03-07).

How do I verify Guillermo Acero's NPI record?

Cross-check NPI 1629144373 against the official CMS registry at npiregistry.cms.hhs.gov. This page mirrors the same public NPPES data with a monthly snapshot.

Other providers at this practice address

Browse all →

Theodore Angus Emergency Medicine Physician · Ojai, CA NPI 1235195256 Elizabeth Patterson Emergency Medicine Physician · Ojai, CA NPI 1477510410 Ojai Valley Emergency Physicians Medical Group Inc Emergency Medicine Physician · Ojai, CA NPI 1134148224

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2023-03-07.