The Defense Department has released final numbers on military folks, by branch of service, who switched into the new Blended Retirement System (BRS) during a year-long opt-in period that ran through Dec. 31. Opt-in rate comparisons across service branches show the singular effectiveness of the Marine Corps' approach to deepening member interest in the BRS, given that it relies more on youth and vigor, and therefore has fewer careerists. Read more about the BRS results in this Military.com story.