Physicians & Staff
PROVIDERS
PHYSICIAN ASSISTANTS
Stacy G. Carr, MPAS, PA-C
Stacy G Carr joined Lone Star Pain Medicine in 2008 as a physician assistant. Stacy graduated from Tarleton State University in Stephenville, Texas with a Bachelor of Science in Animal Biology in May 2001. He then graduated from the University of North Texas Health Science Center in Fort Worth, Texas, where he completed the Masters Physician Assistant Studies in May 2005. Mr. Carr is a nationally certified physician assistant by NCCPA and is licensed by the Texas State Board of Medical Examiners. He has extensive hospital and clinical experience in orthopedics.
Tim Marcyes, MPAS, PA-C
Timothy Marcyes joined Lone Star Pain Medicine in 2014 as a Physician Assistant. He earned a Bachelor’s Degree in psychology and biology from Southwest Texas University in San Marcos, Texas in 1991. While serving in the U.S. Army for 11 years he graduated with his second Bachelor’s Degree in Physician Assistant Studies from The University of Texas Health Science Center in San Antonio, TX in 1998 and later completed his Master’s Degree in Family Medicine from University of Nebraska medical Center in Omaha, Nebraska in 2000. He served in the U.S. Army as a Physician Assistant until 2003 and has worked in pain management since leaving the service.
Carissa Champang, Nurse Manager
Carissa Champang, RN is the Nurse Manager at Lone Star Pain Medicine where she oversees both the clinic and procedure areas. She began her career with the practice in 2020 as a Medical Assistant and has since worked in multiple departments. Carissa earned her Associate Degree in Nursing from Weatherford College in 2024, obtained her RN license in 2025, and stepped into her current Nurse Manager role. With five years’ experience at Lone Star, she is dedicated to delivering exceptional patient care and supporting her teams success. Outside of work, she has been happily married for four years and is a proud dog mom to her bulldog, Roscoe. She enjoys working out, volunteering with her youth at her church and spending time outdoors.
Taylor Johnsen, Physician Assistant
Taylor Johnsen joined Lone Star Pain Medicine in 2022 as a Physician Assistant. She graduated July 2014 with a Bachelors Degree in Biology from the University of West Georgia in Carrollton, Georgia. She then obtained her Master in Physician Assistant Studies May of 2018 from Union College in Lincoln, Nebraska. She is nationally certified by NCCPA and licensed by the Texas State Board of Medical Examiners. She has extensive experience in the hospital and clinic in orthopedics and pain medicine.STAFF
Bethany Murphy, Office Manager
Bethany Murphy joined Lone Star Pain Medicine in 2002 as a billing specialist, and is currently the Office Manager. She oversees patient reception/scheduling, new patient referrals, billing, and provider credentialing. She graduated from Tarleton State University with Bachelor degree in Business Administration. A native of Parker County, she loves spending time with her husband and two children. 
Allison Cargill, Accounting Manager
Allison Cargill joined Lone Star Pain Medicine in 2007. As the Accounting Manager, she is responsible for all accounting functions, including accounts payable and receivable, payroll, banking, account reconciliations, expense budgeting as well as Human Resource related matters. Allison Graduated from Poolville High School in 2007 and went to Weatherford College. She loves spending time outdoors on their family ranch where she resides with her husband and son.
