Quick answers
- Does James J. Gehrig Jr. accept Medicare assignment?
- Yes. Medicare's clinician data says James J. Gehrig Jr. accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of October 2, 2026. Ask the office to confirm before your visit.
- What is James J. Gehrig Jr.'s NPI number?
- 1619049434. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where James J. Gehrig Jr. works
Medicare's Facility Affiliation Data lists James J. Gehrig Jr. at these hospitals (updated October 2, 2026). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians. Star rating and emergency services: Hospital General Information (CMS), data updated October 26, 2026.
- Kaiser Foundation Hospital - San MarcosSan Marcos, CA · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 050855
Practice locations
Addresses where James J. Gehrig Jr. is enrolled with Medicare (CMS data updated October 2, 2026).
- 360 Rush DrSan Marcos, CA 92078 (833) 574‑2273
- 4647 Zion AveSan Diego, CA 92120 (619) 528‑5000
Group practices
Medicare enrollment lists James J. Gehrig Jr. as a member of this group (CMS data updated October 2, 2026).
- Southern California Permanente Medical Group11,293 clinicians in the group
Specialties
- Nephrologyprimary
- Internal Medicinealso
Other nephrologists in San Marcos
Clinicians with the same Medicare primary specialty in San Marcos, CA — not a recommendation.
Other clinicians in Southern California Permanente Medical Group
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | Virginia Commonwealth University, School Of Medicine |
| Graduation year | 1978 (48 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1619049434 |
| Corrections | Report an error or suggest an update → |
Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.
Sources
- Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated October 2, 2026, retrieved October 29, 2026
- Hospital General Information — CMS, data updated October 26, 2026, retrieved November 13, 2026
- National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians