William Yen-Jung Chen, D.D.S.
Endodontics · Fullerton, CA
William Yen-Jung Chen, D.D.S. is an endodontics with a practice address in Fullerton, California, and NPI 1639375991, issued on Jun 25, 2007. Check the license (California 45838, as entered in NPPES) with the California board that licenses this profession; the Medicare figures below come from public CMS files.
- Name
- William Yen-Jung Chen
- Credential
- D.D.S.
- Primary taxonomy
- Endodontics 1223E0200X
- License number
- 45838 CA
Self-reported in NPPES; status is on the state search - Practice location
- 259 Laguna RD, Fullerton, CA 92835
- Phone
- (714) 738-6651
- Enumerated
- Jun 25, 2007
- Record last updated
- Jul 8, 2007 (not updated in 19 years: call before relying on the address or phone)
- Entity
- Type 1 · individual
8 nearest endodontics records → All 1,018 in California → Look up another NPI →
Also registered at 259 Laguna RD
A shared address usually means a shared clinic or building; it does not show who employs whom.
- John Lythgoe, D.D.S.Endodontics1922196716
Verify William Yen-Jung Chen in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWhich California board licenses this profession
Search for license 45838Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
17% fewer Medicare Part D claims than the average endodontics in 2024
101 Medicare Part D claims for 62 beneficiaries, against an average of 121 among the 4,119 providers of this specialty who prescribed in Part D. Brand-name drugs were 0% of claims.
Most prescribed
- Amoxicillin40 claims
- Methylprednisolone37 claims
- Clindamycin Hcl11 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.
Industry payments in 2024: $213.64
7 payments; by number, the most common kind was food and beverage; the largest payer was Sonendo Inc. The 2,057 providers of this specialty with any payment received $49,739.86 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.
William Yen-Jung Chen among 1,018 endodontics records in California
William Yen-Jung Chen, D.D.S. is one of 1,018 endodontics records with a practice address in California. 68% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2007, is newer than 27% of them.
- NPI issued2007 · 27% of these records are older, 42% newer
- In a Medicare fileYes · 68% of these records are
- In the CMS Doctors and Clinicians fileNo · under 1% of these records are
- Record last updated2007 · 78% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 1223E0200X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Endodontics providers in California
There are 1,018 endodontics records in California.
All 1,018 in California → Every provider in Fullerton → Endodontics nationwide →
The 8 endodontics records with the nearest ZIP codes
- John Lythgoe, D.D.S.Fullerton, CA 928351922196716
- Thien Nguyen, D.D.S.Fullerton, CA 928351033234257
- Laura Piroutek, D.M.D.Fullerton, CA 928351366758625
- Esther Cho, DDSFullerton, CA 928321881773315
- Meghna Patel, D.D.SFullerton, CA 928321881190163
- Saman Malkami, DMDFullerton, CA 928311205909132
- Michael Kim, DDS.Garden Grove, CA 928401336476373
- Christine Jung, DDSGarden Grove, CA 928441992959597
Common questions
What is William Yen-Jung Chen, D.D.S.'s NPI number?
William Yen-Jung Chen, D.D.S.'s National Provider Identifier (NPI) is 1639375991, issued on Jun 25, 2007. An NPI identifies a provider in billing; it is not a license.
Where is William Yen-Jung Chen, D.D.S. located?
The NPPES record lists a practice address at 259 Laguna RD, Fullerton, CA, 92835. Phone: (714) 738-6651. Providers update this record themselves, so call before visiting.
How can I verify William Yen-Jung Chen, D.D.S.'s license?
NPPES lists California license number 45838, as entered by the provider. Search the California board that licenses this profession; the NPPES record confirms identity only.
How much does William Yen-Jung Chen, D.D.S. prescribe under Medicare Part D?
In 2024, William Yen-Jung Chen, D.D.S. had 101 Medicare Part D claims for 62 beneficiaries; the average among endodontics prescribers was 121. 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.