sentences:  After the CNMI was added to the North American Numbering Plan, the U.S. Federal Communications Commission (FCC) regulated calls to and from the CNMI as "domestic", hence dramatically lowering the cost of these telephone calls.This change also opened up national toll-free numbers to callers from the CNMI, which became very popular with the advent of pre-paid phone cards.However, since no mobile telephone carriers in the U.S. are present in the CNMI market, cellular calls to the CNMI are not necessarily considered "domestic" or within the definition of "nationwide long distance".