Jonathan Leff, M.D.
NPI 1538407721 · Research Study Specialist · Menlo Park, CA
Jonathan Leff, M.D. is a Research Study Specialist provider in Menlo Park, CA (NPI 1538407721).
Provider details
- NPI number
- 1538407721
- Entity type
- Individual
- Primary specialty
- Research Study SpecialistOther Service Providers
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- Yes
- License
- G86872 (CA)
Specialties & taxonomies
Other Service Providers
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure33% of score
13 yrs in NPPES registry
- Profile completeness33% of score
100% of core fields populated
- Practice footprint20% of score
1 documented practice location
- 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.
$139 across 1 record (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
- 2013-01-22
- Last updated
- 2013-01-22
Frequently asked questions
- What is Jonathan Leff's NPI number?
- Jonathan Leff's National Provider Identifier (NPI) is 1538407721, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Jonathan Leff's specialty?
- Jonathan Leff is listed in the NPPES registry with a primary specialty of Research Study Specialist (Other Service Providers).
- Where is Jonathan Leff located?
- Jonathan Leff's practice location on file with NPPES is 178 Seminary Dr, Menlo Park, CA 94025-3569.
- What is Jonathan Leff's phone number?
- The practice phone number listed in the NPPES registry for Jonathan Leff is (650) 521-0353.
- Is Jonathan Leff's NPI active?
- Yes — Jonathan Leff's NPI (1538407721) is active in the NPPES registry as of the last update on 2013-01-22.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.