Quick answers
- Does Cynthia L. Sierra accept Medicare assignment?
- Yes. Medicare's clinician data says Cynthia L. Sierra 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 Cynthia L. Sierra see?
- In 2024, CMS data shows 25 Original Medicare patients and 46 services for Cynthia L. Sierra. This counts Original Medicare only and measures volume, not quality.
- What is Cynthia L. Sierra's NPI number?
- 1437252905. 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 Cynthia L. Sierra, 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 | 25 |
|---|---|
| Services billed to Medicare | 46 |
| Different services or procedures | 18 |
| Participating Medicare provider | Yes |
| Average age of these patients | 68 |
Most frequent services
- Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)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 pressure68%
Practice locations
Addresses where Cynthia L. Sierra is enrolled with Medicare (CMS data updated October 2, 2026).
- 3955 Bonita RdBonita, CA 91902 (619) 528‑5000
- 4647 Zion AveSan Diego, CA 92120 (619) 528‑5000
Group practices
Medicare enrollment lists Cynthia L. Sierra as a member of this group (CMS data updated October 2, 2026).
- Southern California Permanente Medical Group11,293 clinicians in the group
Specialties
- Family Practiceprimary
Other family doctors in Bonita
Clinicians with the same Medicare primary specialty in Bonita, 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 | University Of California, Davis School Of Medicine |
| Graduation year | 2004 (22 years since medical school) |
| Gender (as listed) | Female |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1437252905 |
| 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