NPIMap

Individual provider Active NPI

Geoffrey Alexander Sonn, MD

  • Urology Physician
  • Stanford, CA
National Provider Identifier
1275720351
Registry record updated Mar 18, 2026
On this page

Key facts

NPPES NPI Registry
Primary specialty
Urology PhysicianTaxonomy code 208800000X
License
A96537 Issued in CA
Practice address
300 Pasteur Dr
Stanford, CA 94305-2200
Phone
(650) 723-4000
NPI assigned
Oct 2, 2007
Sex
Male
Sole proprietor
No

NPPES NPI Registry

Updated by the provider on Mar 18, 2026

Registry information is reported by the provider to CMS and is not verified. About this source

Specialties & licenses 2

Specialty (taxonomy)CodeLicenseStatePrimary
Surgery Physician 208600000X A96537 CA
Urology Physician 208800000X A96537 CA Primary

Addresses

Primary practice location

300 Pasteur Dr
Stanford, CA 94305-2200

Mailing address

300 Pasteur Dr
Stanford, CA 94305-2200
Phone (650) 723-4000

Medicare participation

Medicare enrollment files
Medicare fee-for-service enrollment
Enrolled in CA
Eligible to order & refer
  • Part B services
  • Medical equipment
  • Home health
  • Power mobility devices
  • Hospice
Green means eligible to order or refer.

Enrollment records 1

Enrollment IDStateProvider typePAC IDDetails
I20110627000562 CA Practitioner - UrologyPractitioner - General Surgery 8325226145 Reassigns benefits to 3 organizations

Care Compare profile

Medicare Care Compare
Specialty
UrologyAlso: General Surgery
Education
University of California, Geffen School of Medicine, 2005
Medicare assignment
Accepts the Medicare-approved amount as payment in full
Telehealth
Offers telehealth services
Group practices
Stanford Health CareGroup PAC ID 6709797491, 3,152 clinicians

Practice addresses (Care Compare)

300 Pasteur Dr
Stanford, CA 94305-2200
Phone (650) 723-4000

Hospital & facility affiliations

Merit-based Incentive Payment System (MIPS)

Final score
88.53 of 100Reported as group
Quality
87.08
Promoting interoperability
100
Improvement activities
40
Cost
69.51

Procedures performed for Medicare patients

ProcedureNumber of procedures
Prostate resection23

National Provider Directory

National Provider Directory
Medicare enrollment (NPD)
Enrolled
Credentials
Doctor of Medicine

Practice roles

OrganizationSpecialtyStatusNew patients
Stanford Health Care Surgery Current Accepting new patients
Stanford Health Care CurrentSince Aug 15, 2013 Accepting new patients
County of Los Angeles CurrentSince Mar 31, 2012 Accepting new patients
Stanford Health Care CurrentSince Aug 15, 2013 Accepting new patients
County of Los Angeles CurrentSince Mar 31, 2012 Accepting new patients
Lucile Salter Packard Children'S Hospital at Stanford Past Accepting new patients
Stanford Hospital and Clinics Past Accepting new patients

Locations

1000 S Fremont Ave
Unit 9
Alhambra, CA 91803

911 Sunset Dr
Hollister, CA 95023
Phone (831) 626-2640

875 Blake Wilbur Dr
Palo Alto, CA 94304
Phone (650) 723-7621

1804 Embarcadero Rd
Ste 100
Palo Alto, CA 94303
Phone (650) 497-9067

300 Pasteur Dr
Palo Alto, CA 94304
Phone (650) 723-6469

2589 Samaritan Dr
San Jose, CA 95124
Phone (408) 357-1060

300 Pasteur Dr
Stanford, CA 94305
Phone (650) 498-5710

1000 W Carson St
Torrance, CA 90502
Phone (310) 222-3501

Interoperability endpoints

  • Direct secure messaging: gsonn40410@direct.stanfordhealthcare.org

Organizations & group practices 8

Organizations this provider is connected to: Medicare benefit reassignments (the organization bills Medicare for this provider’s services), Care Compare group memberships and National Provider Directory roles.

Hospital & facility affiliations 10

Hospitals and other facilities this clinician is affiliated with according to Medicare Care Compare.

NPI Registry JSON

The complete NPPES record for this NPI in the NPI Registry API format.

{
    "created_epoch": "1191283200000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1773792000000",
    "number": "1275720351",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "300 PASTEUR DR",
            "city": "STANFORD",
            "state": "CA",
            "postal_code": "943052200",
            "telephone_number": "650-723-4000"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "300 PASTEUR DR",
            "city": "STANFORD",
            "state": "CA",
            "postal_code": "943052200",
            "telephone_number": "650-723-4000"
        }
    ],
    "practiceLocations": [],
    "basic": {
        "last_name": "SONN",
        "first_name": "GEOFFREY",
        "middle_name": "ALEXANDER",
        "credential": "MD",
        "sole_proprietor": "NO",
        "sex": "M",
        "enumeration_date": "2007-10-02",
        "last_updated": "2026-03-18",
        "certification_date": "2026-03-18",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "208600000X",
            "taxonomy_group": "",
            "desc": "Surgery",
            "state": "CA",
            "license": "A96537",
            "primary": false
        },
        {
            "code": "208800000X",
            "taxonomy_group": "",
            "desc": "Urology",
            "state": "CA",
            "license": "A96537",
            "primary": true
        }
    ],
    "identifiers": [],
    "endpoints": [],
    "other_names": []
}

Other providers in Stanford, CA

Sources for this page

Verify at the official NPI Registry.