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Stone Oak Clinic

  • 20821 U.S. Hwy 281 N., Ste. 122
  • San Antonio, TX 78258
  • Mon. Thur. Fri. 7:30 am – 5 pm
    Tues. 7 am – 8 pm
    Wed. 10 am – 5 pm
  • Telephone: (210) 546-1600
  • Fax: (210) 923-2208

ThanhVi D. Nguyen, DO

Dr. ThanhVi D. Nguyen was born in  Vietnam and moved to San Antonio  when she was just four years old. She  considers San Antonio her home as  she graduated from Health Careers  High School and St. Mary’s University.  Dr. Nguyen is Board Certified in Family  Medicine and is fluent in Vietnamese. 

Prior to joining HealthTexas Primary Care Doctors Dr. Nguyen gained  her knowledge and experience in providing quality and compassionate  care to patients while working with  Christus Health during her residency.  Her lifelong dream was always to  become a family physician. 

Dan Powell, MD

Dr. Dan Powell was born in Amarillo, Texas and was raised in the Dallas-Fort Worth area. Dr. Powell attended medical school at the University of Texas Health Science Center, where he received his degree in 1991 and completed his residency program at St. Joseph’s Hospital in Denver, Colorado.

Sergio Hernandez, PA-C

Mr. Hernandez was born and raised in Mission City, Texas of the beautiful Rio Grande Valley. Upon graduating high school, he attended undergraduate school to earn his Bachelor of Science in Biology at the University of Texas-Pan American. He continued his Physician Assistant degree at the University of Texas Rio Grande Valley.

Lorrin Tschirhart, PA-C

Mrs. Lorrin Tschirhart grew up in a small town near Victoria, Texas called Inez. After graduating college, she moved to Fort Rucker, Alabama while her husband was in Army Flight School before moving to San Antonio in 2018.

Mrs. Tschirhart has always had a passion for medicine ever since she was little, but the desire was confirmed in college when she began to learn more in depth about the role of a Physician Assistant. Her passion also grew through volunteering in hospitals, going on mission trips, and being a medical assistant in college.

I am very proud pleased with Dr. Santoscoy I left my old provider because I couldn't get appointments to get in but I've never had that problem here.

Larry S.