Examples disclosed herein relate to provisioning a network device in a stack. In an example, a master network device in a stack may detect a new network device in the stack. In response to detecting, master network device may determine whether a member network device of the stack is missing. In response to determining that the member network device of the stack is missing, master network device may identify each active adjacent member of the member network device. The master network device may determine whether each active adjacent member of the member network device has detected the new network device in the stack. In response to determining that each active adjacent member of the member network device has detected the new network device in the stack, master network device may provision the new network device with a member ID of the member network device to the stack.