Matthew Nienaber, D.O.

Primary specialty

Internal Medicine PhysicianTaxonomy code 207R00000X

License

20A14759 Issued in CA

Practice address

1821 Wilshire Blvd Ste 100
Santa Monica, CA 90403-5627

Phone

(310) 575-3100

Fax

(310) 575-3102

NPI assigned

Mar 13, 2014

Sex

Male

Sole proprietor

No

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

Specialties & licenses 1

Addresses

Electronic endpoints 1

Medicare fee-for-service enrollment

Enrolled in CA

Eligible to order & refer

• Part B services: Yes
• Medical equipment: Yes
• Home health: Yes
• Power mobility devices: Yes
• Hospice: Yes

Green means eligible to order or refer.

Enrollment records 1

Specialty

Internal Medicine

Education

Other, 2014

Medicare assignment

Accepts the Medicare-approved amount as payment in full

Telehealth

Offers telehealth services

Group practices

Providence Saint Johns Medical FoundationGroup PAC ID 0840548624, 282 clinicians

Svmhs ClinicsGroup PAC ID 1456592351, 258 clinicians

Practice addresses (Care Compare)

Hospital & facility affiliations

• Providence Home Health la County South Home health agency, Torrance, CA, CCN 557447
• Saint John'S Health Center Hospital, Santa Monica, CA, CCN 050290
• Salinas Valley Health Medical Center Hospital, Salinas, CA, CCN 050334

Merit-based Incentive Payment System (MIPS)

Final score

90.42 of 100Reported as group

Quality

96.07

Promoting interoperability

100

Improvement activities

40

Cost

71.98

Procedures performed for Medicare patients

Medicare enrollment (NPD)

Enrolled

Credentials

Doctor of Osteopathy

State licenses

Practice roles

Locations

Networks

• BSC 65 PLUS INDIVIDUAL MAPD

Interoperability endpoints

• Direct secure messaging: mnienaber292479@oc.providencedirect.org

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.

• Providence Saint Johns Medical Foundation

  • Specialist
  • Santa Monica, CA
  • NPI 1770093734

  Internal Medicine

  Medicare reassignment Care Compare group NPD
• Svmhs Clinics

  • Multi-Specialty Clinic/Center
  • Salinas, CA
  • NPI 1093158347
  Medicare reassignment Care Compare group
• Nationwide Vitals, Medical Corporation

  • Internal Medicine Physician
  • Los Angeles, CA
  • NPI 1659255958
  Medicare reassignment NPD

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

• Providence Health System - Southern California

  • Home Health Agency
  • Torrance, CA
  • NPI 1700890514
  Care Compare affiliation
• Providence Saint John'S Health Center

  • General Acute Care Hospital
  • Santa Monica, CA
  • NPI 1124026273
  Care Compare affiliation
• Salinas Valley Memorial Healthcare System

  • Rural Health Clinic/Center
  • Gonzales, CA
  • NPI 1437549284

  Hospital

  Care Compare affiliation
• Salinas Valley Memorial Healthcare System

  • General Acute Care Hospital
  • Salinas, CA
  • NPI 1750384079
  Care Compare affiliation

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

{
    "created_epoch": "1394668800000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1779926400000",
    "number": "1033535182",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "1821 WILSHIRE BLVD STE 100",
            "city": "SANTA MONICA",
            "state": "CA",
            "postal_code": "904035627",
            "telephone_number": "310-575-3100"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "1821 WILSHIRE BLVD STE 100",
            "city": "SANTA MONICA",
            "state": "CA",
            "postal_code": "904035627",
            "telephone_number": "310-575-3100",
            "fax_number": "310-575-3102"
        }
    ],
    "practiceLocations": [
        {
            "address_1": "355 Abbott St Ste 100",
            "address_purpose": "LOCATION",
            "city": "Salinas",
            "state": "CA",
            "postal_code": "939014484",
            "country_code": "US",
            "telephone_number": "831-751-7070",
            "fax_number": "831-751-7050",
            "country_name": "United States",
            "address_type": "DOM"
        }
    ],
    "basic": {
        "last_name": "NIENABER",
        "first_name": "MATTHEW",
        "name_prefix": "Dr.",
        "credential": "D.O.",
        "sole_proprietor": "NO",
        "sex": "M",
        "enumeration_date": "2014-03-13",
        "last_updated": "2026-05-28",
        "certification_date": "2026-05-28",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "207R00000X",
            "taxonomy_group": "",
            "desc": "Internal Medicine",
            "state": "CA",
            "license": "20A14759",
            "primary": true
        }
    ],
    "identifiers": [],
    "endpoints": [
        {
            "endpointType": "DIRECT",
            "endpointTypeDescription": "Direct Messaging Address",
            "endpoint": "mnienaber292479@oc.providencedirect.org",
            "affiliation": "N",
            "address_1": "1821 Wilshire Blvd Ste 100",
            "city": "Santa Monica",
            "state": "CA",
            "country_code": "US",
            "postal_code": "904035627",
            "country_name": "United States",
            "address_type": "DOM"
        }
    ],
    "other_names": []
}

• Julia Katherine Nicholls, MA, CCC-SLP
• Nicole Young Nichols, M.S.W.
• Teresa Roxanne Nicolaou, LMFT, PSYD
• Alexander Bryce Williams Niculescu, MD
• Andrew Nielsen-Lyman, PT, DPT
• Manijeh Khakpour Nikakhtar, MD
• Mordechai Saied Nikfar, RPH
• Vahid Niki, DDS
• Nahal Niknam, D.D.S
• Niloufar Ehya Inc

• Internal Medicine Physician in Santa Monica, CA
• Providers in Santa Monica, CA by specialty
• Internal Medicine Physician in California

• NPPES NPI Registry (CMS): identity, addresses, specialties, licenses, identifiers and endpoints. Last updated by the provider on May 28, 2026; self-reported and not verified by CMS. Specialty names from the NUCC taxonomy.
• Medicare enrollment (CMS PECOS): enrollments, PAC IDs and benefit reassignments; Order and Referring.
• Medicare Care Compare (CMS): clinician profile, group practices, facility affiliations, MIPS scores and star ratings.
• National Provider Directory (CMS): practice roles, locations, licenses, networks and endpoints.

Verify at the official NPI Registry.