Provided are a method for a terminal controlling uplink power in a rando access channel-less (RACH-less) handover, and an apparatus for supporting same. The method may comprise the steps of: receiving, from a source base station, an RRC connection reconfiguration message including an uplink grant; transmitting, to a target base station using a first transmission power, an RRC connection reconfiguration complete message, on the basis of the uplink grant; receiving, from the target base station, a NACK corresponding to the RRC connection reconfiguration complete message; ramping the first transmission power to a second transmission power; and transmitting the RRC connection reconfiguration complete message using the ramped second transmission power.