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

William Aaron Markoff, MD

Individual provider Family Medicine Physician · NPI 1407869167

William Aaron Markoff, MD is registered under Family Practice in Santa Rosa, California. Qualified in 1998, 28 years ago. Practices with Providence Medical Foundation, a 1,465-clinician group, accepts Medicare assignment and offers telehealth. Licensed in California.

Years since qualifying
28
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

3536 Mendocino Ave Ste 300
Santa Rosa, CA 95403-3634
Phone: (707) 544-3811
Fax: (707) 544-0128
Show map & directions

Directions in Google Maps · Apple Maps · OpenStreetMap

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

Specialties & licences

Family Medicine Physician (primary) Taxonomy 207Q00000X · Licence A74621 (CA)

Record details

NPI number1407869167
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedAugust 14, 2006
Last updated in NPPESNovember 30, 2021
Certification dateNovember 30, 2021

Medicare enrollment

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

Medicare specialtyFAMILY PRACTICE
Medical schoolOTHER
Graduated 1998 (28 years in practice)
Group practice Providence Medical Foundation — 1465 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
TelehealthOffers telehealth services

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 skin lesions 25 times · 67th percentile

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 patients629
Services billed 3,303 a service is one billed item, such as a visit, a test or a procedure
Average patient age76

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. Those with a page here are linked.

  • Petaluma Valley Hospital Hospital · Petaluma, CA · listed as Petaluma Valley Dental
  • Blc Homehealth Inc Home health agency · San Leandro, CA
  • Bridge Home Health Home health agency · Petaluma, CA · listed as Bridge Home Health East Bay LLC
  • Gateway Home Health Corp. Home health agency · San Ramon, CA · listed as Gateway Home Health Corp
  • Providence Santa Rosa Memorial Hospital Hospital · Santa Rosa, CA
  • Sonoma Valley Hospital Hospital · Sonoma, CA
  • Providence At Home With Compassus Home Health, Sonoma Home health agency · Santa Rosa, CA
  • Sutter Care At Home Home health agency · Santa Rosa, CA

Colleagues at Providence Medical Foundation

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 1465 clinicians in the practice; 12 are shown here.

Other providers in Santa Rosa