William Tseng, M.D.
NPI 1417071242 · Surgical Oncology Physician · Arcadia, CA
Enrolled with Medicare as Practitioner - Surgical Oncology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William Tseng, M.D. is a Surgical Oncology Physician provider in Arcadia, CA (NPI 1417071242).
Provider details
- NPI number
- 1417071242
- Entity type
- Individual
- Primary specialty
- Surgical Oncology PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- A94446 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
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
3 documented practice locations
- Medicare service volume (vs. specialty peers)25% of score
102 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 High Level of Medical Decision Making, If Using Time, 40 Minutes Or More99215 | 74 | $154 |
| New Patient Office Or Other Outpatient Visit With a High Level of Medical Decision Making, If Using Time, 60 Minutes Or More99205 | 28 | $193 |
Typical Medicare-allowed amounts for these services range $154–$193 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, not a price quote 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.
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$2,706 across 2 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
Additional practice locations (2)
- 1500 Duarte RdDuarte, CA 91010-3012Phone: (626) 256-4673
- 209 Fair Oaks AveSouth Pasadena, CA 91030-1814Phone: (626) 396-2900Fax: (626) 799-2889
Registry dates
- Enumerated
- 2007-03-19
- Last updated
- 2022-06-08
- Certified
- 2022-06-08
Frequently asked questions
- What is William Tseng's NPI number?
- William Tseng's National Provider Identifier (NPI) is 1417071242, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Tseng's specialty?
- William Tseng is listed in the NPPES registry with a primary specialty of Surgical Oncology Physician (Allopathic & Osteopathic Physicians).
- Where is William Tseng located?
- William Tseng's practice location on file with NPPES is 301 W Huntington Dr Ste 400, Arcadia, CA 91007-3471.
- What is William Tseng's phone number?
- The practice phone number listed in the NPPES registry for William Tseng is (626) 218-9840.
- Does William Tseng accept Medicare?
- William Tseng is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is William Tseng's NPI active?
- Yes — William Tseng's NPI (1417071242) is active in the NPPES registry as of the last update on 2022-06-08.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.