NPPES file of Aug 9, 2026

Silvia Alonzo, MS, PA-C

Medical Physician Assistant · Diamond Bar, CA

Silvia Alonzo, MS, PA-C is a medical physician assistant with a practice address in Diamond Bar, California, and NPI 1942586623, issued on Oct 26, 2011. Check the license (California PA21842, as entered in NPPES) with the California board that licenses this profession; the Medicare figures below come from public CMS files.

Record from CMS NPPES, file of Aug 9, 2026 · Medicare files 2024 · method · Verify with CMS →

NPPES recordNPPES file of Aug 9, 2026
1942586623
Name
Silvia Alonzo
Credential
MS, PA-C
Primary taxonomy
Medical Physician Assistant 363AM0700X
License number
PA21842 CA
Self-reported in NPPES; status is on the state search
Practice location
1514 Valley Vista Dr, Diamond Bar, CA 91765
Phone
(909) 860-1144
Enumerated
Oct 26, 2011
Record last updated
Oct 14, 2021 (not updated in 5 years: call before relying on the address or phone)
Fax
(909) 860-7684
Medicare enrollment
Enrolled (PECOS I20130719000399); accepts Medicare assignment
Telehealth
Offers telehealth (CMS)
Entity
Type 1 · individual
Public record from CMS NPPES (open it on the CMS NPI Registry). Enrollment, assignment, school and telehealth: CMS Doctors and Clinicians file, Aug 2026. A record is not a license: verify it with the state board.
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Also registered at 1514 Valley Vista Dr

A shared address usually means a shared clinic or building; it does not show who employs whom.

  1. Wilfredo Alejo, M.D.Pediatrics Physician1114990785
  2. Jing Chen, M.D.Pediatrics Physician1699208942
  3. William FenertyFamily Medicine Physician1184625915
  4. Brian Koffman, MDFamily Medicine Physician1326049164
  5. Keli Layton-Cunnigan, PAPhysician Assistant1063613958
  6. Eric Lee, DOFamily Medicine Physician1801208707

Verify Silvia Alonzo in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersWhich California board licenses this profession
    Search for license PA21842
    Check the board
  3. 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
  4. 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
  5. 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Find the California license search

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2.4 times the Medicare Part D claims of the average medical physician assistant in 2024

2,771 Medicare Part D claims for 495 beneficiaries, against an average of 1,148 among the 23,801 providers of this specialty who prescribed in Part D. Brand-name drugs were 11% of claims. 24 claims were for opioids.

  1. Silvia Alonzo2,771
  2. Specialty average1,148

Most prescribed

  1. Atorvastatin Calcium146 claims
  2. Levothyroxine Sodium120 claims
  3. Losartan Potassium106 claims
  4. Amlodipine Besylate96 claims
  5. Rosuvastatin Calcium91 claims
  6. Gabapentin67 claims

Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.

Industry payments in 2024: $165.14

8 payments; by number, the most common kind was food and beverage; the largest payer was GlaxoSmithKline, LLC. The 16,165 providers of this specialty with any payment received $1,055.00 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.

  1. Silvia Alonzo$165.14
  2. Specialty average$1,055.00

Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.

Bills Medicare through one group practice

  1. Providence Medical FoundationFullerton, CA

Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).

Medical Physician Assistant providers in California

There are 3,376 medical physician assistant records in California.

Other medical physician assistant records in California

  1. Bridget Abajian, PA-CLos Angeles, CA1518677061
  2. Crispin Abbott, PHYSICIAN ASSISTANTThousand Oaks, CA1063467926
  3. Abdol Hamid Abdali Hajiabadi, P.A.Santa Ana, CA1285747964
  4. Jilbert Abnoosian, PALynwood, CA1447300314
  5. Reema Aboelrish, PA-CFresno, CA1376466144
  6. Sakina Abowath, P.A.Diamond Bar, CA1326287525
  7. Selin Abraamyan, PA-CGlendale, CA1144795899
  8. Antonious Abraham, PA-CCovina, CA1003434275
  9. Michelle AbrahamSacramento, CA1952875957
  10. Therese Abraham, P.A.-CGlendale, CA1063726586

Common questions

What is Silvia Alonzo, MS, PA-C's NPI number?

Silvia Alonzo, MS, PA-C's National Provider Identifier (NPI) is 1942586623, issued on Oct 26, 2011. An NPI identifies a provider in billing; it is not a license.

Where is Silvia Alonzo, MS, PA-C located?

The NPPES record lists a practice address at 1514 Valley Vista Dr, Diamond Bar, CA, 91765. Phone: (909) 860-1144. Providers update this record themselves, so call before visiting.

How can I verify Silvia Alonzo, MS, PA-C's license?

NPPES lists California license number PA21842, as entered by the provider. Search the California board that licenses this profession; the NPPES record confirms identity only.

How much does Silvia Alonzo, MS, PA-C prescribe under Medicare Part D?

In 2024, Silvia Alonzo, MS, PA-C had 2,771 Medicare Part D claims for 495 beneficiaries; the average among medical physician assistant prescribers was 1,148. Part D covers Medicare prescriptions only.

Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.

Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.