Dr. Mark S. Wallis, M.D.
Mohs Surgery (MOHS-Micrographic Surgery Physician)
- Medicare participating
At a glance
- Medical school
- University of Texas Medical School at San Antonio (1988)
- Years since graduation
- 38
- In the NPI registry since
- 2005
- Medicare patients seen, 2024
- 1,676
Licensed in Texas since 1989, according to the Texas Medical Board. We show license dates only for the states that publish them in bulk; see which states do. For other states, check the state medical board.
The NPI date is when this clinician registered for a National Provider Identifier, the billing number used on health claims. It is not a license, graduation or board-certification date. NPIs were first issued in May 2005 and became required on claims in 2007–2008, so an early date usually means the clinician was already in practice before then. What an NPI is
Education and training
- 1988Medical school: University of Texas Medical School at San Antonio
- 2005Registered with an NPI (national billing number; not a license date) — NPIs began in 2005, so practice likely started earlier
Undergraduate school, residency, fellowship, licensing exams and board certification aren’t in public federal data. Board certification can be confirmed with the certifying board (ABMS member boards for MDs, AOA boards for DOs).
Specialties and state licenses
-
MOHS-Micrographic Surgery Physician primary
TX license H6685 (first issued 1989; active) -
Clinical & Laboratory Dermatological Immunology Physician
TX license H6685 (first issued 1989; active) -
Dermatology Physician
TX license H6685 (first issued 1989; active) -
Dermatopathology Physician
TX license H6685 (first issued 1989; active) -
Pediatric Dermatology Physician
TX license H6685 (first issued 1989; active) -
Procedural Dermatology Physician
TX license H6685 (first issued 1989; active)
As reported to the NPI registry. To confirm a license is current, check the state medical board.
Where they work
Medical groups
- Wallis Dermatology Associates PLLC (12 clinicians)
Hospitals this clinician lists with Medicare, and groups they bill Medicare through (Care Compare). Affiliation doesn’t mean they see patients at every location.
Medicare patients and services
- Medicare patients, 2024
- 1,676
- Services billed
- 12,459
- Patients’ average age
- 76
| Service | Times | Patients |
|---|---|---|
| Aminolevulinic acid hcl for topical administration, 10% gel, 10 mg | 3,000 | 11 |
| Pathology examination of tissue using a microscope, intermediate complexity | 1,864 | 1,147 |
| Destruction of precancer skin growth, 2-14 growths | 1,304 | 199 |
| Established patient office or other outpatient visit, 20-29 minutes | 386 | 293 |
| Destruction of precancer skin growth, 1 growth | 312 | 234 |
| Removal and microscopic exam of growth of head, neck, hands, feet, or genitals, 1-5 tissue blocks | 285 | 222 |
| Removal and microscopic exam of growth of head, neck, hands, feet, or genitals, each additional stage, 1-5 tissue blocks | 143 | 96 |
| Pathology examination of tissue using a microscope, moderately low complexity | 128 | 116 |
| Biopsy of related skin growth, first growth | 114 | 100 |
| Established patient office or other outpatient visit, 30-39 minutes | 113 | 94 |
Medicare fee-for-service only. CMS leaves out services billed for fewer than 11 patients. These figures describe a practice’s Medicare work; they aren’t a measure of quality.
Medicare prescriptions
Prescriptions filled under Medicare Part D, including refills. CMS leaves out drugs prescribed fewer than 11 times.
Payments from drug and device companies
In 2025, 18 companies reported 141 payments worth $2,790 in total to this clinician.
| Food and Beverage | $2,680 |
|---|---|
| Education | $110 |
What the payments were for
| Company | What it was for | Amount |
|---|---|---|
| Sanofi-aventis U.S. LLC Nov 6, 2025 | Education DUPIXENT · Immunology · in-kind | $99.99 |
| AbbVie Inc. Jan 15, 2025 | Education in-kind | $9.65 |
Each payment as the company reported it, with the products it named. Meals are counted in the totals above but not listed one by one.
From CMS Open Payments. A payment is not evidence of wrongdoing; many are for consulting, teaching or meals. Clinicians can review and dispute their records with CMS.