Iun-Iu A. Chen, D.O.
Family Medicine Physician · Petaluma, CA
Iun-Iu A. Chen, D.O. is a family medicine physician with a practice address in Petaluma, California, and NPI 1114288412, issued on Jun 4, 2012. Check the license on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Iun-Iu A. Chen
- Credential
- D.O.
- Primary taxonomy
- Family Medicine Physician 207Q00000X
- License number
- 252070 MA
Self-reported in NPPES; status is on the state search - Practice location
- 1179 N Mcdowell Blvd, Petaluma, CA 94954
- Phone
- (707) 559-7500
- Enumerated
- Jun 4, 2012
- Record last updated
- Jul 1, 2025
- Fax
- (707) 559-7620
- Medicare enrollment
- Enrolled (PECOS I20160128002641); accepts Medicare assignment
- Medical or professional school
- Rutgers New Jersey Medical School, 2012
- Entity
- Type 1 · individual
8 nearest family medicine physician records → All 17,133 in California → Look up another NPI →
Also registered at 1179 N Mcdowell Blvd
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify Iun-Iu A. Chen in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of CaliforniaCheck the board
- 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
56% fewer Medicare Part D claims than the average family medicine physician in 2024
1,561 Medicare Part D claims for 177 beneficiaries, against an average of 3,544 among the 117,163 providers of this specialty who prescribed in Part D. Brand-name drugs were 11% of claims. 41 claims were for opioids.
Most prescribed
- Levothyroxine Sodium91 claims
- Atorvastatin Calcium75 claims
- Lisinopril75 claims
- Amlodipine Besylate62 claims
- Omeprazole43 claims
- Losartan Potassium42 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.
Bills Medicare through one group practice
- Petaluma Health Center IncPetaluma, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Iun-Iu A. Chen among 17,133 family medicine physician records in California
Iun-Iu A. Chen, D.O. is one of 17,133 family medicine physician records with a practice address in California. 81% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2012, is newer than 66% of them.
- NPI issued2012 · 66% of these records are older, 32% newer
- In a Medicare fileYes · 81% of these records are
- In the CMS Doctors and Clinicians fileYes · 62% of these records are
- Graduated2012 · median 2005 among the 10,652 with a school on file
- Record last updated2025 · 58% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207Q00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
46 family medicine physician records list a practice address in Petaluma
They are 46 of the 1,856 NPPES records with a practice address in Petaluma, and 17,133 family medicine physician records in California.
All 17,133 in California → Every provider in Petaluma → Family Medicine Physician nationwide →
The 8 family medicine physician records with the nearest ZIP codes
- Andrew Ashcroft, M.D.Petaluma, CA 949541053306795
- Richard Chen, MDPetaluma, CA 949541285602573
- Jonathan Choe, M.D.Petaluma, CA 949541518959170
- Michelle Davey, DOPetaluma, CA 949541366445785
- Patrick Flynn, M.D.Petaluma, CA 949541770567745
- Colleen Foy Sterling, M.D.Petaluma, CA 949541619969326
- Robert Hentz, MDPetaluma, CA 949541720012107
- Audra Lehman, M.D.Petaluma, CA 949541063404762
Common questions
What is Iun-Iu A. Chen, D.O.'s NPI number?
Iun-Iu A. Chen, D.O.'s National Provider Identifier (NPI) is 1114288412, issued on Jun 4, 2012. An NPI identifies a provider in billing; it is not a license.
Where is Iun-Iu A. Chen, D.O. located?
The NPPES record lists a practice address at 1179 N Mcdowell Blvd, Petaluma, CA, 94954. Phone: (707) 559-7500. Providers update this record themselves, so call before visiting.
How can I verify Iun-Iu A. Chen, D.O.'s license?
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 Iun-Iu A. Chen, D.O. prescribe under Medicare Part D?
In 2024, Iun-Iu A. Chen, D.O. had 1,561 Medicare Part D claims for 177 beneficiaries; the average among family medicine physician prescribers was 3,544. Part D covers Medicare prescriptions only.
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.