Please see important information regarding new Medicare cards which will be mailed between April 2018, and April 2019. You don't need to do anything to receive a new Medicare card. Remember, that Medicare will NEVER call and ask for your personal information before sending new cards, so don't share your Medicare number or other personal information if someone calls and asks for it. Call 1-800-772-1213 or visit https://www.ssa.gov/myaccount/ if you need to update your mailing address.
Your Aetna retiree ID cards are not impacted by this change.