Aaron Si Arn Ranbaduge Leong
NPI 1770939381ActiveIndividual· Internal Medicine, Endocrinology, Diabetes & Metabolism· Boston, MA
Internal Medicine, Endocrinology, Diabetes & Metabolism with Massachusetts General Physicians Organization Inc and 1 other group, practicing in Boston, Massachusetts. Their prescriptions cost Medicare Part D more than their services did: $257,459 for 496 claims, against $26,878 paid for services in 2024. Sanofi-Aventis U.S. LLC was the largest of 3 companies reporting payments in 2025, $282.87 in all, mostly speaking and faculty fees. Lists Brigham and Women's Hospital and 4 other hospitals as hospital affiliations.
Overview
| NPI | 1770939381 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Sole proprietor | No |
| NPI issued | May 12, 2016 |
| Last updated in NPPES | Feb 10, 2022 |
| Certified by provider | Dec 1, 2021 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Endocrinology, Diabetes & Metabolism Primary | 207RE0101X | 266689 | MA |
| Internal Medicine | 207R00000X | 266689 | MA |
| Student in an Organized Health Care Education/Training Program | 390200000X | — | — |
Exclusion screening
| List | Result | Details |
|---|---|---|
| HHS-OIG LEIE · Nov 10, 2026 | No match | Checked by NPI and by name + state |
| North Carolina Medicaid · Nov 11, 2026 | No match | — |
| New York OMIG · Nov 11, 2026 | No match | — |
| Ohio Medicaid · Nov 11, 2026 | No match | — |
| Pennsylvania Medicheck · Nov 11, 2026 | No match | — |
| Washington HCA · Nov 11, 2026 | No match | — |
Official OIG search · How matching works ·Bulk check a roster
Medicare
| Enrollment (PECOS) | Enrolled Practitioner - Endocrinology (MA) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 187 |
|---|---|
| Services billed | 357 across 13 procedure codes |
| Paid by Medicare | $26,878 |
Part D prescriptions in 2024
| Prescriptions (claims) | 496 · 864 30-day fills |
|---|---|
| Patients | 82 |
| Total drug cost | $257,459 |
Education and affiliations
| Graduation year | 2007 |
|---|---|
| Medicare specialty | Endocrinology |
| Secondary specialties | Internal Medicine |
| Telehealth | Offers telehealth |
Medical groups
- Massachusetts General Physicians Organization IncBoston, MA · 3,558 clinicians
- The General Hospital CorporationBoston, MA · 1,267 clinicians
Hospital affiliations
- Brigham and Women's HospitalBoston, MA
- Massachusetts General HospitalBoston, MA
- Newton-Wellesley HospitalNewton, MA
- North Shore Medical Center -Salem, MA
- Wentworth-Douglass HospitalDover, NH
Industry payments (Open Payments)
- 2025$282.87 · 4 payments from 3 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Sanofi-Aventis U.S. LLC | $150.00 | 1 |
| Lexicon Pharmaceuticals, Inc. | $68.33 | 1 |
| Novo Nordisk Inc | $64.54 | 2 |
What the 2025 payments were for
- Compensation for services other than consulting, including serving as faculty or as a speaker at a venue other than a continuing education program$150.00 · 1 payment
- Food and Beverage$68.33 · 1 payment
- Education$64.54 · 2 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
Other endocrinologists in Boston
- 1013025220
- 1013395375
- 1023098605
- 1033473624
- 1043253024
- 1063459386
- 1063603678
- 1073753414
- 1144886961
- 1164746178
- 1205282100
- 1215466586
All 293 endocrinologists in Boston · All endocrinologists in Massachusetts