Recently Updated NPI Information — some details in this NPI profile have been updated in the NPI registry within the last 60 days.

ALLISON ALDEN MERZ-HERRALA MD
NPI 1770112492
Obstetrics & Gynecology - Complex Family Planning in Stanford, CA

Active since April 04, 2020PECOS Enrolled
300 PASTEUR DR, STANFORD, CA 94305(650) 723-4000 Get Directions Write a Review

NPPES record last updated: September 14, 2026. Verified against the NPPES registry weekly; last sync: September 27, 2026.

Record update history: Sep 14, 2026, Jul 23, 2024, Jan 29, 2023 and 2 more (5 updates tracked since 2020).

About Allison Alden Merz-herrala Md NPPES

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

ALLISON ALDEN MERZ-HERRALA MD (NPI 1770112492) is an individual complex family planning provider in Stanford, California, licensed in California (A185547) and active in the NPI registry since April 2020. She is enrolled in Medicare PECOS, maintains 2 additional practice locations, and is a graduate of Harvard Medical School (2020).

NPPES Registry Identity

NPI1770112492
Entity TypeIndividualFemale
Primary Taxonomy207VC0300X
Provider Legal NameALLISON ALDEN MERZ-HERRALACredential: MD
Location Address300 PASTEUR DRStanford, CA 94305-2200
Mailing Address300 Pasteur DrStanford, CA 94305-2200 · (650) 723-4000
Sole ProprietorYes
Medical School CMSHarvard Medical SchoolGraduated 2020
Enumeration DateApril 4, 2020
Last NPPES UpdateSeptember 14, 20265 updates tracked since enumeration
NPPES CertifiedSeptember 14, 2026
✔ NPI 1770112492 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtyObstetrics & Gynecology · Complex Family PlanningAllopathic & Osteopathic Physicians
Taxonomy Code207VC0300X
License✔ Licensed in CA · A185547
Definition
A complex family planning physician specializes in the diagnosis and treatment of individuals with complex reproductive needs. These physicians are experts in abortion and contraception clinical care, research, education, and advocacy.
Also ListedObstetrics & GynecologyTaxonomy 207V00000X · License A185547 (CA)
300 PASTEUR DR, Stanford, CA 94305

Secondary Practice Locations 2

Location 11001 Potrero Ave Bldg 5San Francisco, CA 94110-3518 · Phone (628) 206-3409 · Fax (415) 206-3112
Location 23288 Moanalua RdHonolulu, HI 96819-1469 · Phone (310) 463-4427

Medicare Participation & PECOS CMS

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

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Allison Alden Merz-herrala Md is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.

PECOS PAC ID3476956061
PECOS Enrollment IDI20240802003309
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 94305 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
$156.67 typical visit price
range $70.37 – $206.04
Typical copayment $39.16 (range $17.59 – $51.51)
Most-billed visit code 99204
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.

Other Providers at the Same Location NPPES 20

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

Internal Medicine (Gastroenterology)
300 PASTEUR DR, ALWAY BUILD M211, MC 5187
STANFORD, CA 94305
Radiology (Vascular & Interventional Radiology)
300 PASTEUR DR
STANFORD, CA 94305
Psychiatry & Neurology (Psychiatry)
300 PASTEUR DR
STANFORD, CA 94305
Radiology (Diagnostic Radiology)
300 PASTEUR DR
STANFORD, CA 94305
Nurse Practitioner
300 PASTEUR DR
STANFORD, CA 94305
Neurological Surgery
300 PASTEUR DR
STANFORD, CA 94305
Pathology (Anatomic Pathology & Clinical Pathology)
300 PASTEUR DR, LANE 235
STANFORD, CA 94305
Internal Medicine (Critical Care Medicine)
300 PASTEUR DR
STANFORD, CA 94305

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is Allison Merz-herrala's NPI number?

The NPI number for Allison Merz-herrala is 1770112492. It was assigned to this individual provider in the NPPES registry on April 4, 2020.

Where is Allison Merz-herrala located?

Allison Merz-herrala practices at 300 Pasteur Dr, Stanford, CA 94305. The listed phone number is (650) 723-4000.

What is Allison Merz-herrala's specialty?

The primary specialty registered for this NPI is Obstetrics & Gynecology, specializing in Complex Family Planning, with taxonomy code 207VC0300X.

Is Allison Merz-herrala enrolled in Medicare?

Yes. Allison Merz-herrala is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.

When was this NPI record last updated?

The NPPES record for Allison Merz-herrala was last updated on September 14, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 15 days ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.