Nate Gilman
Do Sea Days during the license grace period count?
Updated: Feb 2
Yes. The Coast Guard looks at your documented Sea Days within the last 5 years based on when the application is submitted.

For example: Let's say you had 355 sea days when your MMC expired, and they all happened in the previous 2 years. During the grace period, (1 year from when your license expired) you spend time on a small boat and acquire 10 more Sea Days. Now when you submit your renewal application, you will have 365 Sea Days in the last five years.
Important Note: Once your MMC reaches the expiration date, you are no longer allowed to work under its endorsements. The 12-month grace period simply allows you to renew your credentials, rather than reapplying.
Your best option is to submit your renewal application early to avoid any interruptions at work.
Read our guide: What to Do When My USCG License is Expiring Soon to stay ahead of things.
Do I need 360 days to renew my MMC license?
No. If you have less than 360 days in the last 5 years, renewing your USCG National endorsements is as simple as an open book take home test for each endorsement!
Check out this post to get more detail if you have fewer than 360 days at the time for renewal:
What do I need to renew my USCG Captains License with less than 360 days

We hope this made your life a little easier and if you have other questions the MM-SEAS team is always here to help!
We do prefer to answer questions live with screen sharing to make both of our lives easier.
We hold free live virtual office hours Monday and Wednesday from 5:00 - 5:30 pm PT inside of mmseas.com under License Guidance and then Daily Office Hours.
Pro MM-SEAS members get access to our daily live office hours Monday thru Friday from 5:00 - 5:30 pm PT. You also get access to unlimited live 1 on 1 calls with one of our USCG Licensing Specialists. Pro MM-SEAS members can access these features inside of mmseas.com under License Guidance.