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

Jon Stephen Portnoff, MD

Individual provider Cardiovascular Disease Physician · NPI 1609874445

Jon Stephen Portnoff, MD is a Cardiovascular Disease (Cardiology) in Ukiah, California. Qualified in 1984, 42 years ago. Practices with Willits Hospital Inc, a 67-clinician group and accepts Medicare assignment. Licensed in California.

Years since qualifying
42
Licensed in
CA
In the registry since
2005
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

260 Hospital Dr Ste 207
Ukiah, CA 95482-4533
Phone: (707) 463-2400
Fax: (707) 463-3520
Show map & directions

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

Specialties & licences

Cardiovascular Disease Physician (primary) Taxonomy 207RC0000X · Licence A43219 (CA)
Interventional Cardiology Physician Taxonomy 207RI0011X · Licence A43219 (CA)

Record details

NPI number1609874445
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedJuly 13, 2005
Last updated in NPPESOctober 25, 2012
Mailing addressPo Box 2739, Ukiah, CA 95482-2739

Medicare enrollment

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

Medicare specialtyCARDIOVASCULAR DISEASE (CARDIOLOGY)
Medical schoolOTHER
Graduated 1984 (42 years in practice)
Group practice Willits Hospital Inc — 67 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
Practice locations6 on file with Medicare

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