Social Security Matters Dear Rusty: How can I maximize my monthly Social Security benefit? I’m already 70 years old – almost 71 now. Signed: Ready to Apply. Dear Ready to Apply: You’ve already maximized your monthly Social Security benefit by waiting until age 70 to apply. Age 70 is when you stop earning delayed retirement credits, which have boosted your monthly benefit amount by 32% over what you would have received at your full retirement age of 66, and by 76% over what you would have received if you had claimed benefits early at age 62. Your maximum Social Security benefit is reached in ...