William Marrero-Leon, M.D
NPI 1336688274 · Medical Oncology Physician · Houston, TX
William Marrero-Leon, M.D is a Medical Oncology Physician provider in Houston, TX (NPI 1336688274).
Provider details
- NPI number
- 1336688274
- Entity type
- Individual
- Primary specialty
- Medical Oncology PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D
- Sex
- Male
- Sole proprietor
- No
- License
- V7258 (TX)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure33% of score
9 yrs in NPPES registry
- Profile completeness33% of score
100% of core fields populated
- Practice footprint20% of score
2 documented practice locations
- Open Payments transparency13% of score
Has Open Payments disclosures (2024)
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 methodology.
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$3,841 across 103 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 (1)
- San JuanSan Juan, PR 00935-1609Phone: (787) 777-3535
Registry dates
- Enumerated
- 2017-02-13
- Last updated
- 2026-04-14
- Certified
- 2026-04-14
Frequently asked questions
- What is William Marrero-Leon's NPI number?
- William Marrero-Leon's National Provider Identifier (NPI) is 1336688274, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Marrero-Leon's specialty?
- William Marrero-Leon is listed in the NPPES registry with a primary specialty of Medical Oncology Physician (Allopathic & Osteopathic Physicians).
- Where is William Marrero-Leon located?
- William Marrero-Leon's practice location on file with NPPES is 1515 Holcombe Blvd, Houston, TX 77030-4000.
- What is William Marrero-Leon's phone number?
- The practice phone number listed in the NPPES registry for William Marrero-Leon is (713) 792-6161.
- Is William Marrero-Leon's NPI active?
- Yes — William Marrero-Leon's NPI (1336688274) is active in the NPPES registry as of the last update on 2026-04-14.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.