Chien-Ko Wu, M.D.
Internal Medicine Physician · Orange, CA
Chien-Ko Wu, M.D. is an internal medicine physician with a practice address in Orange, California, and NPI 1275680829, issued on Jan 5, 2007. Check the license (California A38491, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Chien-Ko Wu
- Credential
- M.D.
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- A38491 CA
Self-reported in NPPES; status is on the state search - Practice location
- 991 N Tustin St, Orange, CA 92867
- Phone
- (714) 639-6162
- Enumerated
- Jan 5, 2007
- Record last updated
- Jul 9, 2007 (not updated in 19 years: call before relying on the address or phone)
- Fax
- (714) 639-5835
- Medicaid ID
- 00A384910 CA
- Medicare enrollment
- Enrolled (PECOS I20120220000077); accepts Medicare assignment
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 17,696 in California → Look up another NPI →
Also registered at 991 N Tustin St
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Grace Wu, MDOphthalmology Physician1306092424
- Meei-Ling Wu, M.D.Ophthalmology Physician1013065184
Verify Chien-Ko Wu in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A38491Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
42% fewer Medicare Part D claims than the average internal medicine physician in 2024
1,831 Medicare Part D claims for 129 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. 16 claims were for opioids.
Most prescribed
- Atorvastatin Calcium108 claims
- Amlodipine Besylate95 claims
- Rosuvastatin Calcium83 claims
- Metformin Hcl75 claims
- Atenolol74 claims
- Levothyroxine Sodium64 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.
Chien-Ko Wu among 17,696 internal medicine physician records in California
Chien-Ko Wu, 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
- Graduated1974 · median 2004 among the 11,065 with a school on file
- Record last updated2007 · 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).
187 internal medicine physician records list a practice address in Orange
They are 187 of the 13,245 NPPES records with a practice address in Orange, and 17,696 internal medicine physician records in California.
All 17,696 in California → Every provider in Orange → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Shenfon Chou, M.D.Orange, CA 928671437334356
- Shilpa Deshmukh, M.D.Orange, CA 928671790723203
- Jeffrey ThomasOrange, CA 928671932337136
- Ivan Yee, D.O.Orange, CA 928671154653640
- Saeed Zanjani, M.D.Orange, CA 928671588809446
- Jane Abdelhadi, M.D.Orange, CA 928681124097100
- Romilla Batra, MDOrange, CA 928681871545038
- Nadia Elihu, M.D.Orange, CA 928681659340156
Common questions
What is Chien-Ko Wu, M.D.'s NPI number?
Chien-Ko Wu, M.D.'s National Provider Identifier (NPI) is 1275680829, issued on Jan 5, 2007. An NPI identifies a provider in billing; it is not a license.
Where is Chien-Ko Wu, M.D. located?
The NPPES record lists a practice address at 991 N Tustin St, Orange, CA, 92867. Phone: (714) 639-6162. Providers update this record themselves, so call before visiting.
How can I verify Chien-Ko Wu, M.D.'s license?
NPPES lists California license number A38491, 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 Chien-Ko Wu, M.D. prescribe under Medicare Part D?
In 2024, Chien-Ko Wu, M.D. had 1,831 Medicare Part D claims for 129 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.