NPIMap

Individual provider Active NPI

Mackenzie Mae Van Loon, PA-C

  • Physician Assistant
  • Stanford, CA
National Provider Identifier
1922560002
Registry record updated Dec 18, 2025
On this page

Key facts

NPPES NPI Registry
Primary specialty
Physician AssistantTaxonomy code 363A00000X
License
58481 Issued in CA
Practice address
300 Pasteur Dr
Stanford, CA 94305-2200
Phone
(650) 723-4000
NPI assigned
Apr 5, 2019
Sex
Female
Sole proprietor
No

NPPES NPI Registry

Updated by the provider on Dec 18, 2025

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

Specialties & licenses 2

Specialty (taxonomy)CodeLicenseStatePrimary
Surgical Physician Assistant 363AS0400X 58481 CA
Physician Assistant 363A00000X 58481 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

Other practice location 1

2425 Samaritan Dr
San Jose, CA 95124-3997
Phone (408) 559-2552

Other names 1

  • Mackenzie Mae Larsen Former name

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
I20201210002902 CA Practitioner - Physician Assistant 7719399070 Reassigns benefits to 2 organizations

Care Compare profile

Medicare Care Compare
Specialty
Physician Assistant
Education
Other, 2020
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

  • Stanford Health Care Hospital, Stanford, CA, CCN 050441

Merit-based Incentive Payment System (MIPS)

Final score
96.69 of 100Reported as group
Quality
90
Improvement activities
40
Cost
78.43

National Provider Directory

National Provider Directory
Medicare enrollment (NPD)
Enrolled
Credentials
Physician Assistant

Practice roles

OrganizationSpecialtyStatusNew patients
Cep America - California CurrentSince Dec 18, 2020 Accepting new patients
Stanford Health Care CurrentSince Apr 28, 2025 Accepting new patients
Stanford Health Care CurrentSince Apr 28, 2025 Accepting new patients
Stanford Health Care Past Accepting new patients

Locations

1601 Cummins Dr
Ste D
Modesto, CA 95358
Phone (510) 851-7423

2425 Samaritan Dr
San Jose, CA 95124
Phone (408) 354-2114

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

Interoperability endpoints

  • Direct secure messaging: mlarsen223113@direct.stanfordhealthcare.org

Organizations & group practices 5

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 7

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": "1554422400000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1766016000000",
    "number": "1922560002",
    "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": [
        {
            "address_1": "2425 Samaritan Dr",
            "address_purpose": "LOCATION",
            "city": "San Jose",
            "state": "CA",
            "postal_code": "951243997",
            "country_code": "US",
            "telephone_number": "408-559-2552",
            "country_name": "United States",
            "address_type": "DOM"
        }
    ],
    "basic": {
        "last_name": "VAN LOON",
        "first_name": "MACKENZIE",
        "middle_name": "MAE",
        "credential": "PA-C",
        "sole_proprietor": "NO",
        "sex": "F",
        "enumeration_date": "2019-04-05",
        "last_updated": "2025-12-18",
        "certification_date": "2025-12-18",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "363AS0400X",
            "taxonomy_group": "",
            "desc": "Physician Assistant, Surgical",
            "state": "CA",
            "license": "58481",
            "primary": false
        },
        {
            "code": "363A00000X",
            "taxonomy_group": "",
            "desc": "Physician Assistant",
            "state": "CA",
            "license": "58481",
            "primary": true
        }
    ],
    "identifiers": [],
    "endpoints": [],
    "other_names": [
        {
            "first_name": "MACKENZIE",
            "last_name": "LARSEN",
            "middle_name": "MAE",
            "code": "1",
            "type": "Former Name"
        }
    ]
}

Other providers in Stanford, CA

Sources for this page

Verify at the official NPI Registry.