Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of October 4, 2026.
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Dr. Mark Zeme, MD

Individual provider Otolaryngology Physician · NPI 1669400388

Dr. Mark Zeme, MD practises Otolaryngology in Castro Valley, California. Graduated from University of Michigan Medical School in 1987, 39 years ago. Practices as a sole proprietor and accepts Medicare assignment. Licensed in California.

Years since qualifying
39
Trained at
University of Michigan Medical School
Licensed in
CA
In the registry since
2006
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

20400 Lake Chabot Rd Ste 301
Castro Valley, CA 94546-5316 Not confirmed with CMS for 12 years — call before visiting
Phone: (510) 889-6673
Fax: (510) 889-0913
Show map & directions

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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Otolaryngology Physician (primary) Taxonomy 207Y00000X · Licence G66448 (CA)

Record details

NPI number1669400388
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorYes
NPI enumeratedJune 29, 2006
Last updated in NPPESMarch 4, 2014

Medicare enrollment

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

Medicare specialtyOTOLARYNGOLOGY
Medical schoolUNIVERSITY OF MICHIGAN MEDICAL SCHOOL
Graduated 1987 (39 years in practice)
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
Practice locations2 on file with Medicare

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.

Upper gastrointestinal (GI) endoscopy for acid reflux 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 patients245
Services billed 905 a service is one billed item, such as a visit, a test or a procedure
Average patient age73

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.

Other providers in Castro Valley