For data communication services gradually dominating in future wireless networks, one crucial problem is to save battery power of data terminals usually requiring much power. A mobility management scheme in IP-based wireless networks is proposed to reduce battery power consumption of mobile hosts. The proposed scheme manages six states: communicating, attention/cell-connected, attention/PA-connected, idle, off/attached, and detached states for efficient management of battery power, radio resources, and network load. Steady state probabilities for mobile host (MH) state transitions are derived using a semi-Markov process approach, and the power-saving effect of the proposed scheme is analyzed. The effects of various input parameters on the steady state probabilities and power consumption are also investigated. The proposed mobility management scheme yields significant power saving in comparison with the current mobility management schemes for Mobile IP-based wireless networks.