He is professionally affiliated with Seton Medical Center Austin, Seton Smithville Regional Hospital, and the University Medical Center Brackenridge. After completing medical school at La Salle University, Mexican Faculty of Medicine and Xochicalco University, he performed his residency at St. Luke's-Roosevelt Hospital Center. Dr. Castillo honors Blue Cross Blue Shield Bronze, Blue Cross Blue Shield HMO, and Blue Cross Blue Shield Gold, as well as other insurance carriers. He has received professional recognition including the following: Texas Super Doctors.