Quick answers
- Does John W. Marcum accept Medicare assignment?
- Yes. Medicare's clinician data says John W. Marcum 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 John W. Marcum's NPI number?
- 1902885957. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where John W. Marcum works
Medicare's Facility Affiliation Data lists John W. Marcum 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.
- Children's Hospital of Los AngelesLos Angeles, CA · Children's Hospital · Emergency services: listed by Medicare · CCN 053302
Practice locations
Addresses where John W. Marcum is enrolled with Medicare (CMS data updated October 2, 2026).
- 4650 W Sunset BlvdLos Angeles, CA 90027 (323) 361‑8408
Group practices
Medicare enrollment lists John W. Marcum as a member of this group (CMS data updated October 2, 2026).
- Childrens Hospital Los Angeles Medical Group Inc295 clinicians in the group
Specialties
Find other Critical Care (Intensivists) doctors in California →
Other critical care doctors in Los Angeles
Clinicians with the same Medicare primary specialty in Los Angeles, CA — not a recommendation.
Other clinicians in Childrens Hospital Los Angeles Medical Group Inc
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of Southern California Keck School Of Medicine |
| Graduation year | 1999 (27 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1902885957 |
| 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