Karen J. Chang-Chen, MD
NPI 1508916495ActiveIndividual· Internal Medicine, Endocrinology, Diabetes & Metabolism· Chesterfield, MO
Internal Medicine, Endocrinology, Diabetes & Metabolism (MD) with Endocrine Associates, LLC, practicing in Chesterfield, Missouri. Their prescriptions cost Medicare Part D more than their services did: $1,586,431 for 3,227 claims, against $45,900 paid for services in 2024. Lilly USA, LLC was the largest of 26 companies reporting payments in 2025, $117,949 in all, mostly speaking and faculty fees. Lists St Lukes Hospital as a hospital affiliation.
Overview
| NPI | 1508916495 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | MD |
| Sole proprietor | No |
| NPI issued | Jan 11, 2007 |
| Last updated in NPPES | Jul 28, 2020 |
| Certified by provider | Jul 28, 2020 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Endocrinology, Diabetes & Metabolism Primary | 207RE0101X | 2006018028 | MO |
| Internal Medicine | 207R00000X | 2006018028 | MO |
Exclusion screening
| List | Result | Details |
|---|---|---|
| HHS-OIG LEIE · Oct 9, 2026 | No match | Checked by NPI and by name + state |
| North Carolina Medicaid · Nov 4, 2026 | No match | — |
| New York OMIG · Nov 4, 2026 | No match | — |
| Ohio Medicaid · Nov 4, 2026 | No match | — |
| Pennsylvania Medicheck · Nov 4, 2026 | No match | — |
| Washington HCA · Nov 4, 2026 | No match | — |
Official OIG search · How matching works ·Bulk check a roster
Medicare
| Enrollment (PECOS) | Enrolled Practitioner - Endocrinology (MO) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 310 |
|---|---|
| Services billed | 680 across 13 procedure codes |
| Paid by Medicare | $45,900 |
Part D prescriptions in 2024
| Prescriptions (claims) | 3,227 · 7,242 30-day fills |
|---|---|
| Patients | 386 |
| Total drug cost | $1,586,431 |
| Generic share | 36% of claims |
Education and affiliations
| Graduation year | 2003 |
|---|---|
| Medicare specialty | Endocrinology |
| Telehealth | Offers telehealth |
Medical group
- Endocrine Associates, LLCChesterfield, MO · 4 clinicians
Hospital affiliation
- St Lukes HospitalChesterfield, MO
Industry payments (Open Payments)
- 2025$117,949 · 277 payments from 26 companies
- 2024$108,248 · 294 payments from 22 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Lilly USA, LLC | $78,209 | 149 |
| Novo Nordisk Inc | $37,989 | 48 |
| Sequel Med Tech, LLC | $440.22 | 17 |
| Dexcom, Inc. | $148.88 | 7 |
| Medtronic, Inc. | $141.59 | 4 |
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$104,424 · 75 payments
- Travel and Lodging$9,248 · 51 payments
- Food and Beverage$4,278 · 151 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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