Even if your retirement is years away, it's a good idea to periodically check in on your Social Security benefits.
(Checking in is getting an extra layer of security. Earlier this month, the Social Security Administration announced it will enable two-factor authentication starting June 10, requiring account holders to log in and provide an additional point of identification via cellphone or email.
"Using two ways to identify you when you log on will help better protect your account from unauthorized use and potential identity fraud," the agency said in its announcement.)
Here are three more Social Security surprises to be aware of:
If you're divorced, you may be able to collect an amount equivalent to half of what your ex is eligible to receive, based on his or her work record. Experts say retirees unaware of this option may be leaving money on the table.
"Divorced benefits and qualifications aren't discussed anywhere on the statement you get in the mail," Rob Kron, head of investment and retirement education for asset management firm BlackRock, told CNBC. "People just don't know they are eligible for this money and often times it goes unclaimed."
You won't need to make contact with your ex to make this work. But you will need to meet a few criteria — among the qualifications, the marriage must have lasted at least 10 years, and you must be currently unmarried and at least age 62.
Among Social Security recipients, 48 percent of married couples and 71 percent of unmarried individuals count on that check for at least half of their income, according to government statistics. Tax treatment of Social Security benefits at the state level can make a big difference in how much of that check you get to keep.
Many states are friendly in this regard: 36, plus Washington, D.C., don't tax Social Security benefits at all, according to Kiplinger. Of the rest, some offer exemptions based on factors like your age or income.
"Deciding when to start taking your Social Security benefits is one of the most important retirement planning decisions we face," Ken Hevert, senior vice president of retirement at Fidelity Investments, told CNBC. "Social Security-related decisions can be complex, with a number of trade-offs."
But timing isn't just about the right age to claim benefits. There's another issue that often flies under the radar — that is, the time it takes between applying for Social Security and receiving your first payment.
You should apply at least three months before you want benefits to kick in. Procrastinate, and you risk an income gap.