 If you've decided that the blended retirement system is right for you, you simply visit your services designated resource to opt in to the BRS. Otherwise, no action is required to remain in the legacy retirement system. If you're in the Army, Navy, or Air Force, you visit DFAS MyPay. To do this, simply visit mypay.dfas.mil. You can then log in using either your common access card or your login ID and password. Under the main menu, select blended retirement system opt in. Now the system will walk you through the opt in process. You'll confirm you've taken the mandatory BRS opt in training and certify you understand the opt in election decision cannot be reversed, even if you change your mind before the December 31, 2018 deadline. Finally, you'll need to verify your date of birth and mailing address for the TSP. After making your opt in decision, don't forget to review your TSP election options. To review your current TSP elections, go back to the main menu and select traditional TSP and Roth TSP. That's it. You'll receive a confirmation email from DFAS SmartDocs to your email on file. Your opt in decision will be reflected in three to seven business days and on your next leave and earning statement.