A modem is provided for a wireless device that is capable of providing service for at least two SIMs. The modem has at least a first set of modem components and a second set of modem components. The modem selectively reconfigures the arrangement of the plural sets of modem components. In a first configuration, the first set of modem components provides wireless connection service for a first SIM of the wireless device and the second set of modem components provides wireless connection service for a second SIM of the wireless device. This allows active wireless connections to be made on behalf of both SIMs simultaneously by the sets of modem components. In a second configuration, the first set of modem components and the second set of modem components provide wireless connection service for the first SIM.