Mark Allan Berk, M.D.
NPI 1235196858ActiveIndividual· Dermatology· Lake Forest, IL
Dermatology (M.D.) with Dermatologists of Illinois, PLLC, practicing in Lake Forest, Illinois. Their prescriptions cost Medicare Part D more than their services did: $1,469,985 for 1,822 claims, against $409,684 paid for services in 2024. Abbvie Inc. was the largest of 4 companies reporting payments in 2025, $180.99 in all, mostly food and beverage.
Overview
| NPI | 1235196858 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | M.D. |
| Sole proprietor | Yes |
| NPI issued | Apr 27, 2006 |
| Last updated in NPPES | Jan 26, 2010 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Dermatology Primary | 207N00000X | 036068947 | IL |
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 - Dermatology (IL) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 1,555 |
|---|---|
| Services billed | 7,681 across 77 procedure codes |
| Paid by Medicare | $409,684 |
Part D prescriptions in 2024
| Prescriptions (claims) | 1,822 · 2,142 30-day fills |
|---|---|
| Patients | 799 |
| Total drug cost | $1,469,985 |
| Generic share | 89% of claims |
Education and affiliations
| Graduation year | 1981 |
|---|---|
| Medicare specialty | Dermatology |
Medical group
- Dermatologists of Illinois, PLLCLake Forest, IL · 12 clinicians
Industry payments (Open Payments)
- 2025$180.99 · 10 payments from 4 companies
- 2024$266.91 · 8 payments from 5 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Abbvie Inc. | $126.89 | 6 |
| E.R. Squibb & Sons, L.L.C. | $31.29 | 2 |
| Botanix Sb Inc | $21.37 | 1 |
| Organon LLC | $1.44 | 1 |
What the 2025 payments were for
- Food and Beverage$180.99 · 10 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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