C.J. O’Donnell plans to leave Hulman Motorsport, where he has served as Chief Marketing Officer for the past five years, at the end of 2018.

“IndyCar, fueled by our tremendous drivers, teams and sponsors, has experienced five years of steady growth,” O’Donnell said in a statement to RACER.com.

“In a short time, we’ve ignited new levels of interest in the IndyCar Series and the Indy 500. I am grateful to Mark Miles for this experience, and very thankful to my entire team for their dedication and hard work. This project is not complete, but I am encouraged by our progress and proud of what we’ve accomplished together.

“My focus now is to provide a smooth transition for my team. We are already working more closely with NBC Sports as our single broadcast partner. I’ll stay on through the end of the calendar year to strengthen that relationship and assist in identifying a new marketing leader for the organization. These are key to ensuring another year of progress for the sport.”

Since O’Donnell’s arrival in November of 2013, his team has added more than one million followers across IndyCar’s social platforms, and contributed to a 23 percent growth in TV viewership. He has also overseen a renewed emphasis on digital marketing and fan engagement.

“We’ve made noteworthy strides at Hulman Motorsports in recent years,” said Hulman & Company CEO Mark Miles. “Our fan base has grown significantly and we’ve seen improvement across all key marketing metrics. I am pleased with our progress and thankful to C.J. for his strong leadership. His passion for the sport, dedication to his team and tireless effort produced meaningful results.”

Coming off a season defined by growing grids, new teams and rising fan interest in next-generation stars like Alexander Rossi, IndyCar’s switch to a single broadcast partner in NBC Sports next year suggests that the series is poised for continued growth. In 2018, NBCSN delivered audiences of 644,000 for Mid-Ohio and 629,000 for Sonoma, making these two broadcasts the second and third most-viewed on the cable network in the past three years. O’Donnell is similarly optimistic about his own future.

“My next steps are defined,” he said. “I plan to get back to the East Coast, reconnect with friends and family, and explore new challenges. I have a few irons in the fire already.”