No reason not to get it now. It does not expire, it has no experience requirements, and the only qualification is that your check does not bounce. Once issued, it is good for the lifetime of the certificate holder. By regulation, at least one flight crewmember must possess one whenever operating outside the territorial airspace of the United States.
It is the most bogus requirement in the world, but it is a box that will have to be checked on almost every job application in the aviation world ... airline, corporate, charter, even some CFI jobs if you're close to Canada or Mexico, or in Florida with the Bahamas so nearby! Do it, get it over with, never worry about it again.
FL270