The taxes you pay on OASDI may not cover all of your retirement expenses. You need to consider your lifestyle and personal circumstances. It's advisable to start saving for retirement as early as you can in the form of taking part in 401(k) plans, IRAs, and Roth IRAs.  Don't worry about not starting early enough. You can still have a savings cushion if you start saving for retirement later in life as long as you strategize. Additionally, you need to consider that some people become disabled or may already have a disability that takes them out of the workforce. This means you'll tap into your benefits earlier depending on the age you were when a disability may have affected you. It's never a bad idea to plan for this.