Jon Stephen Portnoff, M.D.
Cardiovascular Disease Physician · Ukiah, CA
Jon Stephen Portnoff, M.D. is a cardiovascular disease physician with a practice address in Ukiah, California, and NPI 1609874445, issued on Jul 13, 2005. Check the license (California A43219, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Jon Stephen Portnoff
- Credential
- M.D.
- Primary taxonomy
- Cardiovascular Disease Physician 207RC0000X
- License number
- A43219 CA
Self-reported in NPPES; status is on the state search - Practice location
- 260 Hospital Dr, Ukiah, CA 95482
- Phone
- (707) 463-2400
- Enumerated
- Jul 13, 2005
- Record last updated
- Oct 25, 2012 (not updated in 14 years: call before relying on the address or phone)
- Fax
- (707) 463-3520
- Medicaid ID
- 00A432190 CA
- Medicare enrollment
- Enrolled (PECOS I20041123000368); accepts Medicare assignment
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest cardiovascular disease physician records → All 2,574 in California → Look up another NPI →
Also registered at 260 Hospital Dr
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Lynne Coen, M.D.Family Medicine Physician1851375711
- Cara Eberhardt, MDAddiction Medicine (Family Medicine) Physician1174151450
- Samuel Goldberg, M.D.Pediatrics Physician1821072653
Verify Jon Stephen Portnoff in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A43219Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
32% more Medicare Part D claims than the average cardiovascular disease physician in 2024
4,058 Medicare Part D claims for 620 beneficiaries, against an average of 3,078 among the 20,728 providers of this specialty who prescribed in Part D. Brand-name drugs were 21% of claims. 27 claims were for opioids.
Most prescribed
- Eliquis319 claims
- Entresto319 claims
- Nebivolol Hcl310 claims
- Atorvastatin Calcium285 claims
- Amlodipine Besylate212 claims
- Carvedilol175 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.
The MIPS final score for 2023 (Medicare payment program): 84.6 of 100
The Merit-based Incentive Payment System score is reported for this clinician. Four categories are weighted into the final score; the average among 454,083 clinicians with a measured score was 83.5.
Source: CMS Quality Payment Program, MIPS performance year 2023; category weights for 2023 (qpp.cms.gov).
Industry payments in 2024: $134.05
3 payments; by number, the most common kind was food and beverage; the largest payer was Boehringer Ingelheim Pharmaceuticals, Inc. The 16,686 providers of this specialty with any payment received $3,819.56 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.
Bills Medicare through 3 group practices
- Adventist Health Physicians NetworkUkiah, CA
- Ukiah Adventist HospitalUkiah, CA
- Willits Hospital IncWillits, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Jon Stephen Portnoff among 2,574 cardiovascular disease physician records in California
Jon Stephen Portnoff, M.D. is one of 2,574 cardiovascular disease physician records with a practice address in California. 83% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2005, is newer than 0% of them.
- NPI issued2005 · 0% of these records are older, 90% newer
- In a Medicare fileYes · 83% of these records are
- In the CMS Doctors and Clinicians fileYes · 68% of these records are
- Graduated1984 · median 1999 among the 1,742 with a school on file
- Record last updated2012 · 63% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RC0000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Cardiovascular Disease Physician providers in California
There are 2,574 cardiovascular disease physician records in California.
All 2,574 in California → Every provider in Ukiah → Cardiovascular Disease Physician nationwide →
The 8 cardiovascular disease physician records with the nearest ZIP codes
- Benjamin Meyer, M.D.Ukiah, CA 954821447235254
- Dale Morrison, M.D.Ukiah, CA 954821447258280
- James Price, MDSonoma, CA 954761245244755
- Alex Rainow, MDSonoma, CA 954761255577904
- Kenneth Tobin, DOSonoma, CA 954761700962727
- William Bowden, D.O., F.A.C.C.Windsor, CA 954921528133998
- Samer Kabbani, M.D.Eureka, CA 955011851385223
- Robert Lock, MDEureka, CA 955011821079393
Common questions
What is Jon Stephen Portnoff, M.D.'s NPI number?
Jon Stephen Portnoff, M.D.'s National Provider Identifier (NPI) is 1609874445, issued on Jul 13, 2005. An NPI identifies a provider in billing; it is not a license.
Where is Jon Stephen Portnoff, M.D. located?
The NPPES record lists a practice address at 260 Hospital Dr, Ukiah, CA, 95482. Phone: (707) 463-2400. Providers update this record themselves, so call before visiting.
How can I verify Jon Stephen Portnoff, M.D.'s license?
NPPES lists California license number A43219, as entered by the provider. Search the Medical Board of California at https://www.mbc.ca.gov/License-Verification/default.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Jon Stephen Portnoff, M.D. prescribe under Medicare Part D?
In 2024, Jon Stephen Portnoff, M.D. had 4,058 Medicare Part D claims for 620 beneficiaries; the average among cardiovascular disease physician prescribers was 3,078. Part D covers Medicare prescriptions only.
What is Jon Stephen Portnoff, M.D.'s MIPS final score?
The 2023 MIPS final score is 84.6 of 100. The average among 454,083 clinicians with a measured score was 83.5.
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.