Quick answers
- Does Sheri D. Marquez accept Medicare assignment?
- Yes. Medicare's clinician data says Sheri D. Marquez 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 Sheri D. Marquez see?
- In 2024, CMS data shows 28 Original Medicare patients and 688 services for Sheri D. Marquez. This counts Original Medicare only and measures volume, not quality.
- What is Sheri D. Marquez's NPI number?
- 1538149224. 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 Sheri D. Marquez, 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 | 28 |
|---|---|
| Services billed to Medicare | 688 |
| Different services or procedures | 24 |
| Participating Medicare provider | Yes |
| Average age of these patients | 72 |
Most frequent services
- Calculation of radiation therapy dose (77300)96 services
- Radiation treatment management, 5 treatment sessions (77427)63 services
- Continuing radiation therapy consultation per week (77336)62 services
- X-ray during radiation therapy (77417)36 services
- Obtaining data needed to develop the optimal radiation treatment, 3 or more treatment areas or any number of treatment areas where special treatment is involved (77290)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%
- Cancer (breast, colorectal, lung, prostate, endometrial or leukemia/lymphoma)75%
- High cholesterol71%
- Diabetes61%
- Arthritis39%
Practice locations
Addresses where Sheri D. Marquez is enrolled with Medicare (CMS data updated October 2, 2026).
- 2440 E S StLong Beach, CA 90805 (562) 633‑0836
Group practices
Medicare enrollment lists Sheri D. Marquez as a member of this group (CMS data updated October 2, 2026).
- The Oncology Institute Ca, a Professional Corporation113 clinicians in the group
Specialties
- Radiation Oncologyprimary
Other radiation oncologists in Long Beach
Clinicians with the same Medicare primary specialty in Long Beach, CA — not a recommendation.
Other clinicians in The Oncology Institute Ca, a Professional Corporation
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of California, San Francisco School Of Medicine |
| Graduation year | 1995 (31 years since medical school) |
| Gender (as listed) | Female |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1538149224 |
| 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
- 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