There are no national licenses. All carriers acquire licenses for certain markets and then asserable a larger footprint from individual licenses. Cellular spectrum is partitioned by CMA, PCS spectrum is partitioned by MTA or BTA, AWS spectrum is partitioned by CMA, BEA, or REAG.
Cricket won the AWS A-block license for CMA015 (MSP) in FCC auction 72, so they could build out and launch there if they so desired.