We don't register again. Social security administration from time to time will send us notices on what actions we need to take. It surveys recipients overseas on their status but not necessarily in the U.S. Medicare has yearly renew open period for the beneficiaries to review their coverage and make changes if necessary.
For 2017 Medicare coverage, open enrollment is in the fall of 2016, from October 15 to December 7.
Yearly, the participant review and compare their medicare coverage. It would be for your benefit to review all your coverage.
Between January 1–February 14, if you’re in a Medicare Advantage Plan, you can leave your plan and switch to Original Medicare. If you
switch to Original Medicare, you’ll have until February 14 to also join a Medicare Prescription Drug Plan to add drug coverage.
Below quotation and website link are for your further reference.
Please feel free to follow up. Please read on the reference below.
Fiona Chen, MPA, Ph.D., CPA, ABV, CFF, CITP
September & October—Review & compare
Your plan may change. Review any notices from your plan about changes for next year.
Starting in October, use Medicare’s Plan Finder to find a plan that meets your needs
October 15—Open Enrollment begins
This is the one time of year when ALL people with Medicare can make changes to their health and prescription drug plans for the next year.
Decide: October 15 is the first day you can change your Medicare coverage for next year.