Your current MMC will still be valid after the cutoff date, it will just be valid nationally only. BUT, in all honestly I have travelled all over the US, Central America, and Every island down to St. Kitts and have never once ever had anyone ask to see either my license or stcw. I did take advantage of upgrading my license last November so that is grandfathered in. My license now states "National only". However, I do plan to sign up for and take the necessary class to make my license and stcw current worldwide, this summer.