Woo Sung Ahn, MD
Internal Medicine Physician · Lakewood, CA
Woo Sung Ahn, MD is an internal medicine physician with a practice address in Lakewood, California, and NPI 1396807806, issued on Dec 14, 2006. Check the license (California A51408, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Woo Sung Ahn
- Credential
- MD
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- A51408 CA
Self-reported in NPPES; status is on the state search - Practice location
- 20145 S Pioneer Blvd, Lakewood, CA 90715
- Phone
- (562) 916-5020
- Enumerated
- Dec 14, 2006
- Record last updated
- Jul 8, 2007 (not updated in 19 years: call before relying on the address or phone)
- Fax
- (562) 916-5022
- Medicare enrollment
- Enrolled (PECOS I20091111000572); accepts Medicare assignment
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 17,696 in California → Look up another NPI →
Verify Woo Sung Ahn in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A51408Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
5.1 times the Medicare Part D claims of the average internal medicine physician in 2024
16,144 Medicare Part D claims for 669 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 21% of claims. 63 claims were for opioids.
Most prescribed
- Rosuvastatin Calcium1,160 claims
- Atorvastatin Calcium821 claims
- Losartan-Hydrochlorothiazide800 claims
- Amlodipine Besylate732 claims
- Vascepa588 claims
- Metformin Hcl Er580 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: $793.37
39 payments; by number, the most common kind was food and beverage; the largest payer was Novo Nordisk Inc. 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.
Woo Sung Ahn among 17,696 internal medicine physician records in California
Woo Sung Ahn, MD 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 2006, is newer than 5% of them.
- NPI issued2006 · 5% of these records are older, 56% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileYes · 63% of these records are
- Graduated1976 · 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).
23 internal medicine physician records list a practice address in Lakewood
They are 23 of the 1,204 NPPES records with a practice address in Lakewood, and 17,696 internal medicine physician records in California.
All 17,696 in California → Every provider in Lakewood → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Ali Ammar, MDLomita, CA 907171720498645
- Nabil El Sayad, M.D.Lomita, CA 907171134201791
- Edgar El Sayad, M.D.Lomita, CA 907171992102743
- David Keller, MDLomita, CA 907171356393656
- Anjum Qazi, M.D.Lomita, CA 907171538180492
- Sam Abdelmelek, MDLakewood, CA 907121649414855
- Neha Bhansali, M.DLakewood, CA 907121700923893
- Robert Foster, MDLakewood, CA 907121760604052
Common questions
What is Woo Sung Ahn, MD's NPI number?
Woo Sung Ahn, MD's National Provider Identifier (NPI) is 1396807806, issued on Dec 14, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Woo Sung Ahn, MD located?
The NPPES record lists a practice address at 20145 S Pioneer Blvd, Lakewood, CA, 90715. Phone: (562) 916-5020. Providers update this record themselves, so call before visiting.
How can I verify Woo Sung Ahn, MD's license?
NPPES lists California license number A51408, 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 Woo Sung Ahn, MD prescribe under Medicare Part D?
In 2024, Woo Sung Ahn, MD had 16,144 Medicare Part D claims for 669 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.