Derek T. Phan, M.D.
Internal Medicine Physician · Westminster, CA
Derek T. Phan, M.D. is an internal medicine physician with a practice address in Westminster, California, and NPI 1073729588, issued on May 14, 2007. Check the license (California A99908, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Derek T. Phan
- Credential
- M.D.
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- A99908 CA
Self-reported in NPPES; status is on the state search - Practice location
- 9191 Bolsa Ave Ste 205, Westminster, CA 92683
- Phone
- (714) 891-7035
- Enumerated
- May 14, 2007
- Record last updated
- Oct 7, 2009 (not updated in 17 years: call before relying on the address or phone)
- Medicare enrollment
- Enrolled (PECOS I20090604000347); accepts Medicare assignment
- Medical or professional school
- New York Medical College, 2005
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 17,696 in California → Look up another NPI →
Verify Derek T. Phan in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A99908Check 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 internal medicine physician in 2024
4,198 Medicare Part D claims for 238 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 14% of claims. 12 claims were for opioids.
Most prescribed
- Amlodipine Besylate334 claims
- Atorvastatin Calcium288 claims
- Metformin Hcl217 claims
- Rosuvastatin Calcium205 claims
- Losartan Potassium181 claims
- Metoprolol Succinate159 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: $25.17
1 payment: food and beverage; the largest payer was Lilly USA, LLC. The 50,334 providers of this specialty with any payment received $1,303.06 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.
Derek T. Phan among 17,696 internal medicine physician records in California
Derek T. Phan, M.D. is one of 17,696 internal medicine physician records with a practice address in California. 79% 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 44% of them.
- NPI issued2007 · 44% of these records are older, 44% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileYes · 63% of these records are
- Graduated2005 · median 2004 among the 11,065 with a school on file
- Record last updated2009 · 61% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207R00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
43 internal medicine physician records list a practice address in Westminster
They are 43 of the 1,306 NPPES records with a practice address in Westminster, and 17,696 internal medicine physician records in California.
All 17,696 in California → Every provider in Westminster → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Loc Bui, M.D.Westminster, CA 926831023081387
- Andy Ho, M.D.Westminster, CA 926831801850821
- Vu Le, M.D.Westminster, CA 926831013992791
- Dean Ngo, MDWestminster, CA 926831982690582
- Loan Ngo, M.D.Westminster, CA 926831386696144
- Phuc Nguyen, M.D.Westminster, CA 926831134123961
- Vuong Nguyen, M.D.Westminster, CA 926831093701690
- Hoa Nguyen, M.DWestminster, CA 926831619931763
Common questions
What is Derek T. Phan, M.D.'s NPI number?
Derek T. Phan, M.D.'s National Provider Identifier (NPI) is 1073729588, issued on May 14, 2007. An NPI identifies a provider in billing; it is not a license.
Where is Derek T. Phan, M.D. located?
The NPPES record lists a practice address at 9191 Bolsa Ave Ste 205, Westminster, CA, 92683. Phone: (714) 891-7035. Providers update this record themselves, so call before visiting.
How can I verify Derek T. Phan, M.D.'s license?
NPPES lists California license number A99908, 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 Derek T. Phan, M.D. prescribe under Medicare Part D?
In 2024, Derek T. Phan, M.D. had 4,198 Medicare Part D claims for 238 beneficiaries; the average among internal medicine physician prescribers was 3,176. 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.