Merrill Ralph Nisam, MD

Primary specialty

Pulmonary Disease PhysicianTaxonomy code 207RP1001X

License

A45217 Issued in CA

Practice address

1100 Larkspur Landing Cir Ste 10
Larkspur, CA 94939-1836

Phone

(415) 924-1214

Fax

(415) 924-1375

NPI assigned

Oct 6, 2005

Last updated

Dec 16, 2025By the provider in NPPES

Sex

Male

Sole proprietor

No

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

Specialties & licenses 2

Addresses

Other identifiers 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

Critical Care (Intensivists)Also: Pulmonary Disease

Education

University of California, Davis School of Medicine, 1980

Medicare assignment

May accept Medicare assignment

Telehealth

Offers telehealth services

Group practices

Regents Univ of California UCSFGroup PAC ID 6305160300, 276 clinicians

Practice addresses (Care Compare)

Hospital & facility affiliations

• Marinhealth Medical Center Hospital, Greenbrae, CA, CCN 050360
• Novato Community Hospital Hospital, Novato, CA, CCN 050131

Merit-based Incentive Payment System (MIPS)

Final score

81.03 of 100Reported as subgroup

Quality

80.86

Promoting interoperability

76

Improvement activities

40

Cost

75.91

Medicare enrollment (NPD)

Enrolled

Credentials

Doctor of Medicine

State licenses

Practice roles

Locations

Interoperability endpoints

• Direct secure messaging: mnisam84867@direct-ucsfmedicalcenter.org

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.

• Regents Univ of California UCSF

  dba UCSF Physician Group

  • Internal Medicine Physician
  • San Francisco, CA
  • NPI 1124439807

  Critical Care Medicine

  Medicare reassignment Care Compare group NPD
• Aretaeus Telemedicine Inc.

  • Critical Care Medicine (Internal Medicine) Physician
  • Santa Rosa, CA
  • NPI 1548490261
  Medicare reassignment NPD
• Prima Medical Foundation

  • Clinic/Center
  • Novato, CA
  • NPI 1811217946
  Medicare reassignment NPD
• Pulmonary & Critical Care Medicine, Inc.

  dba Merrill R Nisam, MD

  • Critical Care Medicine (Internal Medicine) Physician
  • Mill Valley, CA
  • NPI 1508854381
  NPD (past) Authorized official

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

• Marin General Hospital

  • General Acute Care Hospital
  • Greenbrae, CA
  • NPI 1396725677
  Care Compare affiliation
• Sutter Bay Hospitals

  • General Acute Care Hospital
  • Novato, CA
  • NPI 1104059153
  Care Compare affiliation

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

{
    "created_epoch": "1128556800000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1765843200000",
    "number": "1205824067",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "1100 LARKSPUR LANDING CIR STE 10",
            "city": "LARKSPUR",
            "state": "CA",
            "postal_code": "949391836",
            "telephone_number": "415-924-1214",
            "fax_number": "415-924-1375"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "1100 LARKSPUR LANDING CIR STE 10",
            "city": "LARKSPUR",
            "state": "CA",
            "postal_code": "949391836",
            "telephone_number": "415-924-1214",
            "fax_number": "415-924-1375"
        }
    ],
    "practiceLocations": [],
    "basic": {
        "last_name": "NISAM",
        "first_name": "MERRILL",
        "middle_name": "RALPH",
        "credential": "MD",
        "sole_proprietor": "NO",
        "sex": "M",
        "enumeration_date": "2005-10-06",
        "last_updated": "2025-12-16",
        "certification_date": "2025-12-16",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "207RC0200X",
            "taxonomy_group": "",
            "desc": "Internal Medicine, Critical Care Medicine",
            "state": "CA",
            "license": "A45217",
            "primary": false
        },
        {
            "code": "207RP1001X",
            "taxonomy_group": "",
            "desc": "Internal Medicine, Pulmonary Disease",
            "state": "CA",
            "license": "A45217",
            "primary": true
        }
    ],
    "identifiers": [
        {
            "code": "05",
            "desc": "MEDICAID",
            "issuer": null,
            "identifier": "ZZZ79929Z",
            "state": "CA"
        }
    ],
    "endpoints": [],
    "other_names": []
}

• Ramana K. Naidu, M.D.
• Neurology Health Center, Incorporated
• Nguyen Care Physical Therapy, Inc.
• Hugh Nguyen
• Van Khanh Nguyen, FITTER
• Arvind Nishtala, M.D.
• Northern California Heart Care
• Charles E Odenthal, PSY.D.
• Michael J. Oechsel, M.D.
• Laura Ogrady, M.S.CCC-SLP

• Pulmonary Disease Physician in Larkspur, CA
• Providers in Larkspur, CA by specialty
• Pulmonary Disease Physician in California

• NPPES NPI Registry (CMS): identity, addresses, specialties, licenses, identifiers and endpoints. Last updated by the provider on Dec 16, 2025; 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.