ALLISON ALDEN MERZ-HERRALA MD
NPI 1770112492
Obstetrics & Gynecology - Complex Family Planning in Stanford, CA
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
Specialties & Licenses 2
Secondary Practice Locations 2
Medicare Participation & PECOS CMS
Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.
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.
Medicare Billing Reassignments
4Medicare enrollment records show Allison Merz-herrala reassigns Medicare billing to 4 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Stanford, CA 94305
- Reassigned Medicare billing, California enrollment
- 4,258 clinicians in this Medicare group
Palo Alto, CA 94304
- Reassigned Medicare billing, California enrollment
- 3,617 clinicians in this Medicare group
San Francisco, CA 94124
- Reassigned Medicare billing, California enrollment
- 1,573 clinicians in this Medicare group
San Francisco, CA 94110
- Reassigned Medicare billing, California enrollment
- 842 clinicians in this Medicare group
Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.
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.
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.
STANFORD, CA 94305
STANFORD, CA 94305
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.
Which organizations bill Medicare for Allison Merz-herrala's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Allison Merz-herrala reassigns Medicare benefits to 4 organizations: Stanford Health Care (Stanford, CA), Lpch Medical Group Div Of Lucile (Palo Alto, CA), City & County Of San Francisco (San Francisco, CA) and University Of California Sfgh Medical Group (San Francisco, CA). Each reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for Allison Merz-herrala's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
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 55 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.
# Allison Alden Merz-Herrala, MD · NPI 1770112492
Complex Family Planning physician in Stanford, California. Individual provider, active in the CMS NPPES registry since April 4, 2020.
## Identity
- **NPI:** 1770112492 (Entity type: Individual)
- **Enumerated:** April 4, 2020
- **Primary specialty:** Obstetrics & Gynecology - Complex Family Planning · taxonomy 207VC0300X
- **State license:** A185547 (California)
- **Sole proprietor:** Yes
## Practice location
- **Address:** 300 PASTEUR DR, Stanford, CA 94305-2200
- **Phone:** (650) 723-4000
## Medicare
- **Medicare:** Enrolled (PECOS); accepts Medicare assignment
- **Ordering & referring:** eligible for Part B labs & imaging, durable medical equipment, home health, power mobility devices
- **Bills Medicare through:** 4 organizations under Medicare reassignment (form CMS-855R): Stanford Health Care (NPI 1437292927, Stanford, CA); Lpch Medical Group Div Of Lucile (NPI 1417907940, Palo Alto, CA); City & County Of San Francisco (NPI 1184351082, San Francisco, CA); University Of California Sfgh Medical Group (NPI 1174598296, San Francisco, CA) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Harvard Medical School, class of 2020
## Record status
- **NPPES last updated:** September 14, 2026
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Source: [NPI Profile](https://npiprofile.com/npi/1770112492) · Data from the CMS NPPES public registry.