Those races include Las Vegas Motor Speedway, Phoenix International Raceway, Texas Motor Speedway, Talladega Superspeedway, Bristol Motor Speedway, and Chicagoland Speedway. On February 2, 2015, Snap Fitness returned to the No. 40 team for a second year, sponsoring the races at Atlanta, the All-Star Showdown, Charlotte Motor Speedway, Michigan International Speedway, and Darlington Raceway. On February 11, it was announced that Cassill would partner with Carsforsale.com for a second year. Carsforsale.com sponsored the Daytona 500 and five other Sprint Cup races in the 2015 season. He ran very strongly in the 2015 Coke Zero 400, but his underfunded car was involved in a massive crash on the last lap at the checkered flag; he would finish 13th. With Hillman joining Premium Motorsports, Cassill lost his No. 40 ride. In 2016, Cassill joined Front Row Motorsports, driving the No. 38 Ford Fusion. During the Texas race, a big one occurred on lap 271, Cassill barely made it through. Cassill had his best performance of the season in the Food City 500, where he led 20 laps on a contrary fuel strategy to a 22nd-place finish. Cassill returned to FRM in 2017, though he drove the No. 34 as David Ragan returned to the team in the No. 38. His main sponsors were Starkey Hearing Foundation, CSX (Play it safe), and Love's Travel Stops. It was announced on October 10, 2017, that Cassill would not be returning to Front Row Motorsports in 2018. 2018–2023 After losing his ride in 2017, Cassill came into the 2018 season as a free agent. Following the release of Jeffrey Earnhardt from StarCom Racing, Cassill was announced as the new driver of the No. 00 Chevrolet Camaro with sponsorship from the United States First Responders Association beginning at Martinsville. Cassill finished last after mechanical failure took the car out of the event. The following race proved much better, as Cassill finished 21st. Cassill would return once again at Bristol with sponsorship from Superior Essex and TW Cable where he would finish in the 20th position. At Homestead, he drove the No. 89 car fielded by Morgan Shepherd's Shepherd Racing Ventures team. On December 17, 2018, it was announced that Cassill would drive the No. 00 car full-time in 2019. During the year, Cassill had the lowest crash rate among Cup drivers. In April 2019, Cassill returned to JD Motorsports for the Talladega Xfinity race, driving the No.