Our San Antonio - Stone Oak location has closed. Dr. Petr will now see all patients at U.S. Dermatology Partners San Antonio.

Mark Koone, MD, FAAD


Board-Certified Dermatologist
Fellow of the American Academy of Dermatology

Dr. Mark Koone is board-certified by the American Board of Dermatology and has been in private dermatology practice since 1990. He has practiced with U.S. Dermatology Partners in Texoma – Sherman and Paris, formerly Texoma Dermatology Clinic, since 1993, and he serves as a dermatologist for the Austin College Student Clinic.

Dr. Koone earned a bachelor’s degree magna cum laude from Houston Baptist University with majors in chemistry and biology. He earned a Doctor of Medicine with high honor at Baylor College of Medicine and served an internal medicine internship with Baylor College of Medicine–St. Luke’s Episcopal Hospital. His dermatology residency was served at Duke University Medical Center.

While in practice in Sherman, he has been selected to “Best Doctors in America” every year from 1995 to 2015, has been named a “Texas Super Doctor” in Texas Monthly each year from 2008 to 2015, won the Patient’s Choice Award in 2008 and 2009, and has been named one of “America’s Top Dermatologists” every year from 2008 to 2015.

He currently is a member of the Texas Dermatological Society, where he has been a trustee. He has served as an advisory board member of the American Academy of Dermatology and as president of the Dallas Dermatologic Society. He and his wife have one adult child who lives in Houston.

Clinic Locations

U.S. Dermatology Partners Sherman
U.S. Dermatology Partners Sherman

815 Pecan Grove Road E.
Sherman, TX 75090

(903) 892-2126

U.S. Dermatology Partners Paris
U.S. Dermatology Partners Paris

2725 NE Loop 286
Paris, TX 75460

(903) 579-7290

What Our Patients Say

Mark Koone, MD
5 Stars  As always, my appointment with Dr. Koone was fantastic. He always takes the time to answer any questions I may have and any treatment is handled quickly. It is a pleasure to have him treating any and all skin conditionsthat I may exhibit during my appointments. I highly recommend him to anyone needing a dermatologist. –
Source : Healthgrades – Nov 16, 2018
Mark Koone, MD
5 Stars  Dr Koone and his staff have always treated us promptly and well. –
Source : Healthgrades – Nov 15, 2018
Mark Koone, MD
5 Stars  Dr.Koone is a very good doctor. Takes time with his patients to explain things. My husband and I really have the utmost confidence in him. –
Source : Healthgrades – Nov 14, 2018

Services Offered By Dr. Koone