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

Mary Ann Ambrose, MSN, FNP-C

Family Nurse Practitioner in Paso Robles, CA · enumerated 2005.

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

National Provider Identifier

1811993991

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Registry record

Entity type Individual (Type 1)

Name Mary Ann Ambrose

Credential MSN, FNP-C

Sex Female

Practice address Paso Robles, CA, 93446

Phone (805) 748-5663

Enumeration date Jun 23, 2005

Last updated in NPPES Aug 28, 2012

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

Taxonomy & licenses

363LF0000X Family Nurse Practitioner Physician Assistants & Advanced Practice Nursing Providers · License NP12654 (CA) Primary

163W00000X Registered Nurse Nursing Service Providers · License RN094333 (AZ) Secondary

Other identifiers

Identifier	Type	State	Issuer
5854236	Medicaid	CA	-
P00011916	Other	CA	MEDICARE RAILROAD CARRIER

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 1811993991 active?

Yes, as of the latest NPPES snapshot, NPI 1811993991 is active (record last updated 2012-08-28).

How do I verify Mary Ann Ambrose's NPI record?

Cross-check NPI 1811993991 against the official CMS registry at npiregistry.cms.hhs.gov. This page mirrors the same public NPPES data with a monthly snapshot.

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2012-08-28.