ROSA AHN-HORST MD MPH
NPI 1649822420
Psychiatry & Neurology - Psychiatry in Palo Alto, CA

Q: What is Rosa Ahn-horst's NPI number?

The NPI number for Rosa Ahn-horst is 1649822420. It was assigned to this individual provider in the NPPES registry on July 12, 2019.

Q: What is Rosa Ahn-horst's specialty?

The primary specialty registered for this NPI is Psychiatry & Neurology, specializing in Psychiatry, with taxonomy code 2084P0800X.

Q: When was this NPI record last updated?

The NPPES record for Rosa Ahn-horst was last updated on November 6, 2025. NPI Profile syncs with the weekly NPPES data releases published by CMS.

Active since July 12, 2019PECOS Enrolled

401 QUARRY RD, PALO ALTO, CA 94304(650) 723-5511 Get Directions Write a Review

NPPES record last updated: November 6, 2025. Verified against the NPPES registry weekly; last sync: July 19, 2026.

Record update history: Nov 6, 2025, Oct 9, 2025, Mar 27, 2021 and 1 more (4 updates tracked since 2019).

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About Rosa Ahn-horst Md Mph NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

ROSA AHN-HORST MD MPH (NPI 1649822420) is an individual psychiatry provider in Palo Alto, California, licensed in California (A201644) and active in the NPI registry since July 2019. She is enrolled in Medicare PECOS.

NPPES Registry Identity

NPI1649822420

Entity TypeIndividualFemale

Primary Taxonomy2084P0800X

Provider Legal NameROSA AHN-HORSTCredential: MD MPH

Location Address401 QUARRY RDPalo Alto, CA 94304-1419

Mailing Address401 Quarry RdPalo Alto, CA 94304-1419

Phone(650) 723-5511

Sole ProprietorNo

Enumeration DateJuly 12, 2019

Last NPPES UpdateNovember 6, 20254 updates tracked since enumeration

NPPES CertifiedNovember 6, 2025

✔ NPI 1649822420 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtyPsychiatry & Neurology · PsychiatryAllopathic & Osteopathic Physicians

Taxonomy Code2084P0800X

License✔ Licensed in CA · A201644

Definition

A Psychiatrist specializes in the prevention, diagnosis, and treatment of mental disorders, emotional disorders, psychotic disorders, mood disorders, anxiety disorders, substance-related disorders, sexual and gender identity disorders and adjustment disorders. Biologic, psychological, and social components of illnesses are explored and understood in treatment of the whole person. Tools used may include diagnostic laboratory tests, prescribed medications, evaluation and treatment of psychological and interpersonal problems with individuals and families, and intervention for coping with stress, crises, and other problems.

Also ListedStudent in an Organized Health Care Education/Training ProgramTaxonomy 390200000X · License A201644 (CA)

401 QUARRY RD, Palo Alto, CA 94304

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Medicare Participation & PECOS CMS

Medicare enrollment, assignment, and ordering and referring status from the CMS PECOS system.

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Rosa Ahn-horst Md Mph is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 94304 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient

$206.04 typical visit price

range $70.37 – $206.04

Typical copayment $51.51 (range $17.59 – $51.51)

Most-billed visit code 99205

Established Patient

$86.56 typical visit price

range $23.96 – $169.60

Typical copayment $21.64 (range $5.99 – $42.40)

Most-billed visit code 99213

Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.