Nope. While you can opt to tap your 401(k) at any time (though you’ll pay a huge penalty to do so before age 59.5), you can’t collect your pension until you’ve reached the retirement age determined by your pension plan. Typically full retirement age 65, though many plans allow an early retirement that could start as soon as age 55. If you decide to start receiving benefits before you reach full retirement age, the size of your monthly payout will be less than it would have been if you'd waited. Ask the folks who run your plan to create a simple table showing you how your payments will vary depending on when you start.