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

Mary A Timmerman, FNP

Primary Care Nurse Practitioner in Petaluma, CA · enumerated 2013.

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

National Provider Identifier

1427485465

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Registry record

Entity type Individual (Type 1)

Name Mary A Timmerman

Credential FNP

Sex Female

Practice address Petaluma, CA, 94954

Phone (707) 778-6019

Enumeration date Oct 5, 2013

Last updated in NPPES Oct 5, 2013

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

Taxonomy & licenses

363LP2300X Primary Care Nurse Practitioner Physician Assistants & Advanced Practice Nursing Providers · License 18181 (CA) Primary

FNP · Family Nurse Practitioner: A nurse practitioner certified in family practice across the lifespan. About the FNP credential

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

Where does Mary Timmerman practice?

The practice location on file with NPPES is in Petaluma, CA. Providers can have multiple locations; NPPES lists the primary practice address.

What is the NPI number for Mary Timmerman?

The National Provider Identifier (NPI) for Mary Timmerman is 1427485465, a Type 1 (individual) record in the CMS NPPES registry.

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2013-10-05.