Woo Sung Ahn, MD
NPI 1396807806 · Internal Medicine Physician · Lakewood, CA
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Woo Sung Ahn, MD is a Internal Medicine Physician provider in Lakewood, CA (NPI 1396807806).
Provider details
- NPI number
- 1396807806
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- A51408 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
19 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)25% of score
699 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our .
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 487 | $98 |
| Insertion of Needle Into Vein for Collection of Blood Sample36415 | 171 | $9 |
| Routine Electrocardiogram (ecg) Using at Least 12 Leads With Interpretation and Report93000 | 16 | $16 |
| Telephone Medical Discussion With Physician, 11-20 Minutes99442 | 14 | $75 |
| New Patient Office Or Other Outpatient Visit With Low Level of Medical Decision Making, If Using Time, 30 Minutes Or More99203 | 11 | $120 |
Typical Medicare-allowed amounts for these services range $9–$120 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, and not what you would be billed. Medicare Part B covers roughly an eighth of all NPIs (65+ skew); services with fewer than 11 beneficiaries are suppressed by CMS. Source: CMS Medicare Physician & Other Practitioners, by Provider & Service.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 155 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Rosuvastatin Calcium | 1,160 | 311 |
| Atorvastatin Calcium | 821 | 208 |
| Losartan/Hydrochlorothiazidebrand: Losartan-Hydrochlorothiazide | 800 | 188 |
| Amlodipine Besylate | 732 | 187 |
| Icosapent Ethylbrand: Vascepa | 588 | 115 |
| Metformin Hclbrand: Metformin Hcl Er | 580 | 134 |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$793 across 39 records (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-12-14
- Last updated
- 2007-07-08
Frequently asked questions
- What is Woo Sung Ahn's NPI number?
- Woo Sung Ahn's National Provider Identifier (NPI) is 1396807806, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Woo Sung Ahn's specialty?
- Woo Sung Ahn is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Woo Sung Ahn located?
- Woo Sung Ahn's practice location on file with NPPES is 20145 S Pioneer Blvd, Lakewood, CA 90715-1051.
- What is Woo Sung Ahn's phone number?
- The practice phone number listed in the NPPES registry for Woo Sung Ahn is (562) 916-5020.
- Does Woo Sung Ahn accept Medicare?
- Woo Sung Ahn is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Woo Sung Ahn's NPI active?
- Yes — Woo Sung Ahn's NPI (1396807806) is active in the NPPES registry as of the last update on 2007-07-08.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.