Excited states in the Z = 19, N = 29 neutron-rich 48 K isotope have been studied using deepinelastic transfer reactions with a thick target at Gammasphere and with a thin target at the PRISMA-CLARA spectrometer. The lowest excited states were located; they involve a proton hole in the s 1/2 or d 3/2 orbital coupled to a p 3/2 neutron. A new 7.1(5) ns, 5 + isomer, analog of the 7/2 − isomer in 47 K, was identified. Based on the observed γ-decay pattern of the isomer a revised spin-parity assignment of 1 − is proposed for the ground state of 48 K.