Kelsey Marie Nielsen

Primary specialty

Behavior AnalystTaxonomy code 103K00000X

License

1-23-66175 Issued in CA

Practice address

3731 6TH Ave Ste 100
San Diego, CA 92103-4383

Phone

(855) 223-7123

NPI assigned

Jan 2, 2019

Last updated

Sep 18, 2025By the provider in NPPES

Sex

Female

Sole proprietor

No

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

Specialties & licenses 1

Addresses

Medicare fee-for-service enrollment

Not listed in the public Medicare enrollment file

Medicare enrollment (NPD)

Not enrolled

Practice roles

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

• Growjoy ABA

  • Behavior Analyst
  • Chula Vista, CA
  • NPI 1275406118
  NPD Authorized official
• Behavioral Beginnings Inc.

  • Early Intervention Provider Agency
  • San Diego, CA
  • NPI 1912769332

  Behavior Analyst

  NPD (past)
• Blooming Behavior Services

  • Community/Behavioral Health Agency
  • San Diego, CA
  • NPI 1285236422
  NPD (past)

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

{
    "created_epoch": "1546387200000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1758153600000",
    "number": "1407329493",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "16782 VON KARMAN AVE STE 11",
            "city": "IRVINE",
            "state": "CA",
            "postal_code": "926062417",
            "telephone_number": "855-223-7123"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "3731 6TH AVE STE 100",
            "city": "SAN DIEGO",
            "state": "CA",
            "postal_code": "921034383",
            "telephone_number": "855-223-7123"
        }
    ],
    "practiceLocations": [],
    "basic": {
        "last_name": "NIELSEN",
        "first_name": "KELSEY",
        "middle_name": "MARIE",
        "sole_proprietor": "NO",
        "sex": "F",
        "enumeration_date": "2019-01-02",
        "last_updated": "2025-09-18",
        "certification_date": "2025-09-18",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "103K00000X",
            "taxonomy_group": "",
            "desc": "Behavior Analyst",
            "state": "CA",
            "license": "1-23-66175",
            "primary": true
        }
    ],
    "identifiers": [],
    "endpoints": [],
    "other_names": []
}

• Jael Niebla, BSN
• Leo Niehorster-Cook
• Austin Dean Nielsen
• Ena D. Nielsen, MD
• Flannery Nielsen
• Kristen Renee Nielsen
• Michael Warren Nielsen, MD
• Sydney Nielsen
• Sylvia Fay Nielsen, PT, MPH
• Travis Brady Nielsen, MD, PHD, MPH

• Behavior Analyst in San Diego, CA
• Providers in San Diego, CA by specialty
• Behavior Analyst in California

• NPPES NPI Registry (CMS): identity, addresses, specialties, licenses, identifiers and endpoints. Last updated by the provider on Sep 18, 2025; self-reported and not verified by CMS. Specialty names from the NUCC taxonomy.
• National Provider Directory (CMS): practice roles, locations, licenses, networks and endpoints.

Verify at the official NPI Registry.