William Stephen Knapp, D.O.
NPI 1023099140ActiveIndividual· Family Medicine, Geriatric Medicine· Florissant, MO
Family Medicine, Geriatric Medicine (D.O.) in Florissant, Missouri, trained at At Still University of Health Sciences, College of Osteo Med, Kirksville (class of 1978). Their prescriptions cost Medicare Part D more than their services did: $1,387,533 for 17,182 claims, against $38,540 paid for services in 2024. Astrazeneca Pharmaceuticals LP was the largest of 15 companies reporting payments in 2025, $1,251 in all, mostly food and beverage.
Overview
| NPI | 1023099140 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | D.O. |
| Sole proprietor | No |
| NPI issued | Nov 7, 2005 |
| Last updated in NPPES | Feb 8, 2019 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Family Medicine, Geriatric Medicine Primary | 207QG0300X | R8885 | 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 - Internal Medicine (MO) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 115 |
|---|---|
| Services billed | 1,688 across 65 procedure codes |
| Paid by Medicare | $38,540 |
Part D prescriptions in 2024
| Prescriptions (claims) | 17,182 · 39,222 30-day fills |
|---|---|
| Patients | 875 |
| Total drug cost | $1,387,533 |
| Generic share | 89% of claims |
Education and affiliations
| Medical school | At Still University of Health Sciences, College of Osteo Med, Kirksville |
|---|---|
| Graduation year | 1978 |
| Medicare specialty | Internal Medicine |
Medical group
- American Multispecialty Group IncSaint Charles, MO · 116 clinicians
Hospital affiliations
- Barnes-Jewish St Peters HospitalSaint Peters, MO
- Christian Hospital NortheastSaint Louis, MO
- Mercy Hospital St LouisSaint Louis, MO
- Ssm Health Depaul Hospital St LouisBridgeton, MO
Other facilities
- Ssm Health Rehabilitation HospitalInpatient rehabilitation facility · Richmond Heights, MO
Industry payments (Open Payments)
- 2025$1,251 · 88 payments from 15 companies
- 2024$832.41 · 61 payments from 12 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Astrazeneca Pharmaceuticals LP | $387.32 | 39 |
| Glaxosmithkline, LLC. | $200.20 | 14 |
| Lilly USA, LLC | $162.05 | 8 |
| Abbvie Inc. | $128.55 | 6 |
| Pfizer Inc. | $80.53 | 4 |
What the 2025 payments were for
- Food and Beverage$1,251 · 88 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records