Low-cost carrier Spirit Airlines announced Tuesday that on all reservations made after April 5 for travel beginning Aug. 1, a fee will apply for carry-on bags that are stored in the overhead bin. Simply put, the fee will be $20 for the carrier's Fare Club members and $30 for nonmembers who book in advance, while those who pay at the gate will be charged $45. Passengers who reserve and pay online in advance will receive priority-boarding status. Items excluded from the fee include umbrella, camera, infant diaper bag, assistive devices, outer garments, car seat/stroller, reading material and food for the flight. One carry-on that fits underneath the seat remains free as well. The charge represents "the next phase of unbundling" fees, according to Spirit. More details on the airline's bag fees may be found at spiritair.com/policiesbags.aspx.