Our Team

The physicians, staff and every member of our team here at Next Generation Pediatrics is committed to providing quality personal care to our patients while embracing their role in nurturing a child’s emotional, physical and cognitive development.

Our team consists of experienced pediatricians, physician assistants and friendly staff members who are truly passionate about what we do. We take great joy in watching our young patients grow throughout the years, and look forward to building a relationship with you and your family.


James P. Mortimer, D.O.

Dr. Mortimer is a native of Butler and has been practicing in the community since 2001. He obtained his undergraduate degree from Washington & Jefferson College in 1993. He earned his medical degree from Midwestern University Chicago College of Osteopathic Medicine in 1997. Dr. Mortimer returned to Pittsburgh for an internship at St. Francis Medical Center in 1998. His residency training was at Mercy Hospital in Pittsburgh which was completed in 2001. Dr. Mortimer has been Board Certified in pediatrics since 2001. He returned to his hometown to practice general pediatrics and founded Next Generation Pediatrics in 2003. His special interests include pediatric asthma, musculoskeletal injuries, and care of complicated neonates.

Robyn I. McKnight, M.D.

Dr. McKnight is originally from eastern Pennsylvania and has been living in the Pittsburgh area since 2011. She graduated from the University of Hartford with a degree in biology, then earned her medical degree from Temple University in 2008. She completed her residency training at West Virginia University in 2011 and has been Board Certified in Pediatrics since 2012. Dr. McKnight spent about 5 years practicing general pediatrics in Westmoreland County before joining Next Generation Pediatrics which is not far from her husband’s hometown of Harrisville. She loves interacting with children of all ages and has a special interest in developmental pediatrics and infectious disease. When she is not seeing patients, she enjoys rooting for all three Pittsburgh sports teams, reading, and having fun with her husband, son, and dog.

Shelly Suski, PA-C, IBCLC

Shelly currently resides in the Pittsburgh area, where she attended graduate school, but she grew up in Belle Vernon, PA. She received her Bachelor of Science in Biology from California University of Pennsylvania in 2011, then gained a Masters of Physician Assistant Studies in 2013, from the University of Pittsburgh. Shelly began her career in the field of internal medicine, where she gained valuable experience, but realizing that her passion resided in pediatric medicine is what brought her to Next Generation Pediatrics. Shelly is especially interested in allergies, endocrine, and gastrointestinal disorders.


McKenzie Calhoun, PA-C

McKenzie currently resides in the Butler area, where she grew up. She received her Bachelor of Health Sciences from Saint Francis University in 2016, and then received her Masters of Physician Assistant Sciences in 2017 from Saint Francis University. Since starting her journey in the medical field, McKenzie has always had a strong interest in pediatric medicine which led her to Next Generation Pediatrics. McKenzie is especially interested in allergies and genetic disorders. In her free time, she enjoys reading, spending time with family and enjoying outdoor activities.


Sonja Downing, Front Office Supervisor

Taylor Ray, Receptionist

Chelsea Lindey, Receptionist

Karen Wise, Receptionist


KC Curry-Penrod, RN

Lisa Henderson, RN

Kelly Ruby, CMA

Jim Isaac, LPN

Sherri Hixon, LPN


Kelli Sovek, Office Manager

Jackie Reay, Billing Manager