Mark Lewis Vandewalker, M.D.
NPI 1386833358ActiveIndividual· Allergy & Immunology, Allergy· Columbia, MO
Allergy & Immunology, Allergy (M.D.) in Columbia, Missouri, trained at Washington University School of Medicine (class of 1974). Their prescriptions cost Medicare Part D more than their services did: $198,222 for 652 claims, against $105,771 paid for services in 2024. Astrazeneca Pharmaceuticals LP was the largest of 10 companies reporting payments in 2025, $698.41 in all, mostly food and beverage.
Overview
| NPI | 1386833358 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | M.D. |
| Sole proprietor | No |
| NPI issued | Oct 16, 2007 |
| Last updated in NPPES | Oct 16, 2007 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Allergy & Immunology, Allergy Primary | 207KA0200X | R2F17 | 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 10, 2026 | No match | — |
| New York OMIG · Nov 10, 2026 | No match | — |
| Ohio Medicaid · Nov 10, 2026 | No match | — |
| Pennsylvania Medicheck · Nov 10, 2026 | No match | — |
| Washington HCA · Nov 10, 2026 | No match | — |
Official OIG search · How matching works ·Bulk check a roster
Medicare
| Enrollment (PECOS) | Enrolled Practitioner - Allergy/Immunology (MO) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 233 |
|---|---|
| Services billed | 9,448 across 18 procedure codes |
| Paid by Medicare | $105,771 |
Part D prescriptions in 2024
| Prescriptions (claims) | 652 · 875 30-day fills |
|---|---|
| Patients | 140 |
| Total drug cost | $198,222 |
| Generic share | 58% of claims |
Education and affiliations
| Medical school | Washington University School of Medicine |
|---|---|
| Graduation year | 1974 |
| Medicare specialty | Allergy/Immunology |
Medical group
- Psf PLLCMilford, OH · 98 clinicians
Hospital affiliation
- Boone Hospital CenterColumbia, MO
Industry payments (Open Payments)
- 2025$698.41 · 31 payments from 10 companies
- 2024$408.87 · 20 payments from 8 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Astrazeneca Pharmaceuticals LP | $235.19 | 11 |
| Novartis Pharmaceuticals Corporation | $112.03 | 6 |
| Glaxosmithkline, LLC. | $105.08 | 5 |
| Greer Laboratories, Inc. | $95.57 | 1 |
| Genzyme Corporation | $37.08 | 2 |
What the 2025 payments were for
- Food and Beverage$698.41 · 31 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
Other Allergy & Immunology, Allergy providers in Columbia
- 1205063500
- 1902095979