Quick answers
- Does John W. Zamarra accept Medicare assignment?
- Yes. Medicare's clinician data says John W. Zamarra 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.
- How many Medicare patients does John W. Zamarra see?
- In 2024, CMS data shows 486 Original Medicare patients and 593 services for John W. Zamarra. This counts Original Medicare only and measures volume, not quality.
- What is John W. Zamarra's NPI number?
- 1518052489. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Medicare activity in 2024
Official CMS public-use data for John W. Zamarra, data year 2024 (released May 21, 2026). It covers Original Medicare (fee-for-service) patients only, not Medicare Advantage or other insurance. It shows volume, not quality or outcomes. CMS hides any count of 10 or fewer patients.
| Original Medicare patients | 486 |
|---|---|
| Services billed to Medicare | 593 |
| Different services or procedures | 15 |
| Participating Medicare provider | Yes |
| Average age of these patients | 77 |
Most frequent services
- Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report only (93010)411 services
- Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)93 services
- Ultrasound of heart with color-depicted blood flow, rate, direction and valve function (93306)25 services
- Telephone medical discussion with physician, 5-10 minutes (99441)19 services
- Exercise or drug-induced heart stress test with electrocardiogram (ecg) with supervision by physician (93016)13 services
Chronic conditions among these patients
Share of this clinician’s Original Medicare patients with each condition, as published by CMS (it describes the patients, not the care given).
- High blood pressure75%
- High cholesterol75%
- Arthritis52%
- Diabetes40%
- Atrial fibrillation38%
- Heart failure37%
Hospitals where John W. Zamarra works
Medicare's Facility Affiliation Data lists John W. Zamarra 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.
- Bear Valley Community HospitalBig Bear Lake, CA · Critical Access Hospital · Emergency services: listed by Medicare · CCN 051335
- UCI Health-OrangeOrange, CA · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 050348
Practice locations
Addresses where John W. Zamarra is enrolled with Medicare (CMS data updated October 2, 2026).
- PO BoxBig Bear Lake, CA 92315
- PO Box, Suite 1649Big Bear Lake, CA 92315
Group practices
Medicare enrollment lists John W. Zamarra as a member of this group (CMS data updated October 2, 2026).
- Bear Valley Community Health Care District31 clinicians in the group
Specialties
Other internal medicine doctors in California
Clinicians with the same Medicare primary specialty in California — not a recommendation.
Other clinicians in Bear Valley Community Health Care District
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | State University Of New York At Buffalo School Of Medicine |
| Graduation year | 1975 (51 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1518052489 |
| 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
- Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
- 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