Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.
NPIDirectory

William E Toppen, MD

Individual provider Internal Medicine Physician · NPI 1215399407

William E Toppen, MD practises Undersea and Hyperbaric Medicine in San Diego, California. Graduated from University of California, Geffen School of Medicine in 2016, 10 years ago. Practices with Regents of the University of California, a 2,061-clinician group, works from 3 locations and accepts Medicare assignment. Licensed in California.

Years since qualifying
10
Trained at
University of California, Geffen School of Medicine
Licensed in
CA
In the registry since
2016
Specialties on file
2
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

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Practice location Address checks out

200 W Arbor Dr
San Diego, CA 92103-9000
Phone: (800) 926-8273
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Additional practice locations (2)

  • 9300 Campus Point Dr, La Jolla, CA 92037-1300 — (800) 926-8273
  • 757 Westwood Plz, Los Angeles, CA 90095-7419 — (310) 825-7417

Specialties & licences

Undersea and Hyperbaric Medicine (Emergency Medicine) Physician (primary) Taxonomy 207PE0005X · Licence A155816 (CA)
Internal Medicine Physician Taxonomy 207R00000X · Licence A155816 (CA)

Record details

NPI number1215399407
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedMarch 25, 2016
Last updated in NPPESJanuary 29, 2025
Certification dateJanuary 29, 2025

Medicare enrollment

From the CMS Doctors & Clinicians file — this clinician is enrolled in Medicare.

Medicare specialtyUNDERSEA AND HYPERBARIC MEDICINE
Also practisesHOSPITALIST, INTERNAL MEDICINE
Medical schoolUNIVERSITY OF CALIFORNIA, GEFFEN SCHOOL OF MEDICINE
Graduated 2016 (10 years in practice)
Group practice Regents Of The University Of California — 2061 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount

Procedures

From CMS Care Compare, which counts the procedures a clinician billed to Original Medicare and Medicare Advantage over a recent 12-month period. CMS reports a fixed list of common procedures, so this is not everything the clinician does. Counts of 10 or fewer are given as a range, because CMS withholds small numbers.

Removal of tissue 65 times · 81st percentile
Removal of skin lesions 1–10 times

The percentile compares how often this clinician performed the procedure with other clinicians who performed it, as CMS calculates it. It measures volume, not outcomes or skill.

Medicare patients and services, 2024

From the CMS Medicare Physician & Other Practitioners file for calendar year 2024. It counts Original Medicare patients only, so a practice that mostly sees Medicare Advantage or privately insured patients looks smaller here than it is.

Medicare patients177
Services billed 473 a service is one billed item, such as a visit, a test or a procedure
Average patient age72

Dollar amounts are not shown. What Medicare pays a practice is gross billings, before staff, premises and tax and including the cost of any drugs it administers, so it is not what a clinician earns.

Practises at

Facilities the CMS Facility Affiliation file lists for this clinician.

Colleagues at Regents of the University of California

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 2061 clinicians in the practice; 12 are shown here.

Other providers in San Diego