En español | Q. I turn 62 in September and want to start benefits as soon as I can. Can I apply before I reach my birthday?

A. You can. Social Security will accept your application for early benefits when you're 61 years 9 months. Regardless of how old you are, the agency generally recommends that you apply three months before you would like the first payment to arrive. You'll be asked to provide a series of original documents such as birth records, marriage certificates, military records and tax returns. Make sure you get them all together properly. Problems with documents can slow the approval process.

See also: How to apply for Social Security benefits online.

But I'm afraid that even if you apply in advance with all your paperwork in order, you can't expect to get a check right after your birthday.

That's because benefits are paid only for months in which you qualify for the full month. Unless your birthday is Sept. 1 or 2, Social Security will treat you as not qualifying for September at all. Your first qualifying month will be October. And the benefit for a qualifying month is paid the following month, meaning October's money wouldn't show up in your bank account until November.

You should know, too, that your monthly payment date will depend on your birth date. If you were born between the first and 10th of the month, you'll be paid on the second Wednesday of the month. Birthdays between the 11th and 20th mean payment on the third Wednesday of the month, and birthdays between the 21st and the 31st are paid on the fourth Wednesday of the month.

I hope you've thought out the consequences of applying for benefits at the earliest possible age: You'll be accepting a monthly amount that's 25 percent below what you'd get if you wait until your full retirement age, 66. This AARP Social Security Benefits calculator can help you work out the numbers.

Stan Hinden, a former columnist for the Washington Post, wrote How to Retire Happy: The 12 Most Important Decisions You Must Make Before You Retire. Have a question for the Social Security Mailbox? Check out the archive. If you don't find your answer there, send a query.

You may also like: Have your say about Social Security ... now.

Remember to go to the AARP home page every day for tips on keeping healthy and sharp, and great deals.