David Allen Chappell, M.D.
NPI 1598732463ActiveIndividual· Internal Medicine, Endocrinology, Diabetes & Metabolism· Petaluma, CA
Internal Medicine, Endocrinology, Diabetes & Metabolism (M.D.) in Petaluma, California, trained at University of Texas Southwestern Medical School at Dallas (class of 1979). Their prescriptions cost Medicare Part D more than their services did: $975,415 for 3,900 claims, against $136,178 paid for services in 2024. Lilly USA, LLC was the largest of 14 companies reporting payments in 2025, $1,244 in all, mostly food and beverage.
Overview
| NPI | 1598732463 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | M.D. |
| Sole proprietor | Yes |
| NPI issued | Mar 1, 2006 |
| Last updated in NPPES | Jul 16, 2010 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Endocrinology, Diabetes & Metabolism Primary | 207RE0101X | C40326 | CA |
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 (CA) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 203 |
|---|---|
| Services billed | 2,449 across 24 procedure codes |
| Paid by Medicare | $136,178 |
Part D prescriptions in 2024
| Prescriptions (claims) | 3,900 · 7,277 30-day fills |
|---|---|
| Patients | 232 |
| Total drug cost | $975,415 |
| Generic share | 73% of claims |
Education and affiliations
| Medical school | University of Texas Southwestern Medical School at Dallas |
|---|---|
| Graduation year | 1979 |
| Medicare specialty | Endocrinology |
| Telehealth | Offers telehealth |
Hospital affiliations
- Adventist Health ClearlakeClearlake, CA
- Novato Community HospitalNovato, CA
- Petaluma Valley HospitalPetaluma, CA
- Providence Santa Rosa Memorial HospitalSanta Rosa, CA
- Sonoma Valley HospitalSonoma, CA
Other facilities
- Sutter Care at HomeHome health agency · Santa Rosa, CA
Industry payments (Open Payments)
- 2025$1,244 · 51 payments from 14 companies
- 2024$1,791 · 74 payments from 17 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Lilly USA, LLC | $241.54 | 10 |
| Novo Nordisk Inc | $224.68 | 10 |
| Boehringer Ingelheim Pharmaceuticals, Inc. | $147.91 | 6 |
| Xeris Pharmaceuticals, Inc. | $138.32 | 6 |
| Bayer Healthcare Pharmaceuticals Inc. | $125.03 | 5 |
What the 2025 payments were for
- Food and Beverage$1,244 · 51 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
Other endocrinologists in Petaluma
- 1821267162