John Stephen Hammes, M.D.

Primary specialty

Nephrology PhysicianTaxonomy code 207RN0300X

License

G84351 Issued in CA

Practice address

8885 Rio San Diego Dr Ste 212
San Diego, CA 92108-1626

Phone

(619) 299-2350

Fax

(619) 297-8379

NPI assigned

Jan 28, 2006

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

Other identifiers 3

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

NephrologyAlso: Internal Medicine

Education

Uniformed Services Uhs Fe Hebert School of Med, 1993

Medicare assignment

Accepts the Medicare-approved amount as payment in full

Telehealth

Offers telehealth services

Group practices

Emergency and Acute Care Medical CorporationGroup PAC ID 9537108279, 431 clinicians

Balboa Nephrology Medical Group IncGroup PAC ID 9638164015, 78 clinicians

Practice addresses (Care Compare)

Hospital & facility affiliations

• FMC-Gateway Dialysis Center - East Dialysis facility, San Diego, CA, CCN 052678
• FMC-Balboa South Bay Home Therapies Dialysis facility, Chula Vista, CA, CCN 552677
• Fresenius Medical Care Balboa - Kearny Mesa Dialysis facility, San Diego, CA, CCN 052576
• Scripps Mercy Hospital Hospital, San Diego, CA, CCN 050077
• Sharp Coronado Hospital and Hlthcr Ctr Hospital, Coronado, CA, CCN 050234
• Grossmont Hospital Hospital, La Mesa, CA, CCN 050026

Medicare enrollment (NPD)

Enrolled

Credentials

Doctor of Medicine

State licenses

Practice roles

Locations

Networks

• BSC 65 PLUS INDIVIDUAL MAPD

Interoperability endpoints

• Direct secure messaging: jhammes10413@direct.acumenmd.com
• Direct secure messaging: jhammes28315@scrippshlth.medalliesdirect.net

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.

• Balboa Nephrology Medical Group, Inc.

  • Nephrology Physician
  • San Diego, CA
  • NPI 1316997505
  Medicare reassignment Care Compare group NPD
• Emergency and Acute Care Medical Corporation

  • Emergency Medicine Physician
  • San Diego, CA
  • NPI 1437103942
  Medicare reassignment Care Compare group NPD
• On Call Specialists Medical Group of San Diego, Inc.

  • Specialist
  • San Diego, CA
  • NPI 1962175836
  Medicare reassignment NPD
• Regents of the University of California

  • Family Medicine Physician
  • San Diego, CA
  • NPI 1578672184
  Medicare reassignment NPD
• Balboa Nephrology Medical Group,Inc.

  • Ambulatory Surgical Clinic/Center
  • San Diego, CA
  • NPI 1598276404
  NPD
• Regents of the University of California

  • Nephrology Physician
  • San Diego, CA
  • NPI 1003934803
  NPD
• Regents of the University of California

  • Diagnostic Radiology Physician
  • San Diego, CA
  • NPI 1558463927
  NPD
• Scripps Health

  • General Acute Care Hospital
  • San Diego, CA
  • NPI 1487928891
  NPD
• Regents of the University of California

  • Pharmacy
  • San Diego, CA
  • NPI 1598786576
  NPD (past)
• Scripps Health

  • Clinical Medical Laboratory
  • La Jolla, CA
  • NPI 1427034990
  NPD (past)
• Sharp Chula Vista Medical Center

  • Skilled Nursing Facility
  • Chula Vista, CA
  • NPI 1538142369
  NPD (past)

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

• Fresenius Medical Care Balboa, LLC

  • End-Stage Renal Disease (ESRD) Treatment Clinic/Center
  • San Diego, CA
  • NPI 1376784389

  Dialysis facility

  Care Compare affiliation Name & address match
• Fresenius Medical Care Balboa, LLC

  • End-Stage Renal Disease (ESRD) Treatment Clinic/Center
  • Chula Vista, CA
  • NPI 1588988646

  Dialysis facility

  Care Compare affiliation Name & address match
• San Diego Dialysis Services, Inc.

  • End-Stage Renal Disease (ESRD) Treatment Clinic/Center
  • San Diego, CA
  • NPI 1386756187

  Dialysis facility

  Care Compare affiliation Name & address match
• Grossmont Hospital Corporation

  • General Acute Care Hospital
  • La Mesa, CA
  • NPI 1528041811
  Care Compare affiliation
• Scripps Health

  • General Acute Care Hospital
  • San Diego, CA
  • NPI 1659359446
  Care Compare affiliation
• Sharp Coronado Hospital and Healthcare Center

  • General Acute Care Hospital
  • Coronado, CA
  • NPI 1154304475
  Care Compare affiliation

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

{
    "created_epoch": "1138406400000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1787097600000",
    "number": "1891766994",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "9373 HAZARD WAY STE 200",
            "city": "SAN DIEGO",
            "state": "CA",
            "postal_code": "921231226",
            "telephone_number": "858-810-0000",
            "fax_number": "858-268-1911"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "8885 RIO SAN DIEGO DR STE 212",
            "city": "SAN DIEGO",
            "state": "CA",
            "postal_code": "921081626",
            "telephone_number": "619-299-2350",
            "fax_number": "619-297-8379"
        }
    ],
    "practiceLocations": [],
    "basic": {
        "last_name": "HAMMES",
        "first_name": "JOHN",
        "middle_name": "STEPHEN",
        "name_prefix": "Dr.",
        "credential": "M.D.",
        "sole_proprietor": "NO",
        "sex": "M",
        "enumeration_date": "2006-01-28",
        "last_updated": "2026-08-19",
        "certification_date": "2026-08-19",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "207RN0300X",
            "taxonomy_group": "",
            "desc": "Internal Medicine, Nephrology",
            "state": "CA",
            "license": "G84351",
            "primary": true
        }
    ],
    "identifiers": [
        {
            "code": "01",
            "desc": "Other (non-Medicare)",
            "issuer": "SO CA MEDICARE PTAN",
            "identifier": "CB204086",
            "state": "CA"
        },
        {
            "code": "01",
            "desc": "Other (non-Medicare)",
            "issuer": "CA LICENSE",
            "identifier": "G84351",
            "state": "CA"
        },
        {
            "code": "01",
            "desc": "Other (non-Medicare)",
            "issuer": "NO CA MEDICARE PTAN",
            "identifier": "CA125550",
            "state": "CA"
        }
    ],
    "endpoints": [],
    "other_names": []
}

• Jaclyn Hammer
• Michael Hammer, MSW
• Rachel Hammerlsey
• Danielle A. Hammerman, MD
• Jerrod Hammes, MD
• Ian Hammett, PA-S
• Don P. Hammi, MD
• Katherine Zweier Hammock
• Kyndal Hammock
• Tucker Harrison Hammock

• Nephrology Physician in San Diego, CA
• Providers in San Diego, CA by specialty
• Nephrology Physician in California

• NPPES NPI Registry (CMS): identity, addresses, specialties, licenses, identifiers and endpoints. Last updated by the provider on Aug 19, 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.