Pretty straightforward to resolve assuming continuity of the current system. As an example, if Puerto Rico were to join as a state, then the number of states become 51.

Should the United States cease to exist (e.g., the States disband the constitution and go in alone), the market will resolve as less than 50 states.

If things get really weird (e.g., multiple entities with competing and somewhat legitimate claims to be the United States), I’ll resolve as N/A.