2011 A/T Optima kicks out of gear @40-45MPH

I have the car since new, it has 14,500 miles. While coasting at 40-45 mph then resuming light acceleration the rpms jump up and zoom until I back off the gas! Like it went into neuteral or out of gear. It happens sporadicly, not all the time. I haven't gone to the dealer yet but I wanted to get some input from you guys. Thanks if you can help.