You can't work until your new MMC is in hand. Renew 8 months before expiring to avoid a lapse.
No. You will not be able to work on your MMC until you have your new one in your hands.

If you renew within 8 months of expiration, your new MMC will be post dated to the day after your current MMC expires. This ensures that you have no lapse of your valid USCG license and that you don't lose any of the five years you paid for on both licenses.
If you’re navigating the complexities of a USCG license renewal, we’ve got you covered. No matter which license you hold, whether it’s a Six-Pack, 25 Ton, 50 Ton, or 100 Ton Captain License, we have tailored guides to simplify the process. Start with the Ultimate USCG License Renewal Checklist for a comprehensive overview, or dive into our specific guides to ensure a smooth renewal for your license type.
We hope this made your life a little easier and if you have other questions the MM-SEAS team is always here to help!
MM-SEAS is free to use on your own and if you need some more personalized help you can upgrade to MM-SEAS Expert Access inside of the site.
No matter what, when you are ready to submit your application you can do it yourself, or you can hand the whole thing to us. A Stress-Free MMC is $399. Two MM-SEAS licensing experts check every page, we pay your Coast Guard fees at submission and charge your card so you never touch pay.gov, and we stay on it with the National Maritime Center until your credential is issued.
MM-SEAS Expert Access is $99 a year. It is your personal guidance counselor for USCG licensing: what training you need next, which sea time counts, and how to reach the credential you want, by phone, email, chat or a 1 on 1 video call. Expert Access members also get $50 off a Stress-Free MMC.
Nate Gilman is President and Co-Founder of MM-SEAS. He hawsepiped from the deck to a 3rd Mate Unlimited license with full STCW compliance over more than 15 years at sea, and is a veteran of the NOAA Commissioned Corps. He works directly with the National Maritime Center, USCG-approved training schools, and vessel operators on credentialing policy, and writes on sea service documentation, evaluation standards, and how mariners move up the license ladder.