Social Security is, for millions of Americans, the financial backbone of retirement. Yet the decisions surrounding it are routinely mishandled, sometimes costing retirees tens of thousands of dollars over the course of a lifetime.
The rules are complicated, the tradeoffs are real, and the consequences of getting it wrong are permanent. These are the nine mistakes that show up again and again, and that are worth understanding well before filing day arrives.
1. Claiming Too Early
The most common mistake is also the most expensive. Anyone born in 1960 or later has a full retirement age of 67. Claiming at 62, the earliest possible age, locks in a benefit that’s permanently reduced by up to 30 percent.
On a $2,000 monthly benefit, that’s $600 less every month, every year, for the rest of a person’s life. For healthy individuals who are likely to live into their 80s or beyond, waiting almost always produces a higher lifetime payout. The math heavily favors patience.
2. Not Knowing Your Full Retirement Age
Full retirement age isn’t 65 for everyone anymore. That threshold shifted years ago, and plenty of people still assume the old rules apply. For anyone born between 1943 and 1954, full retirement age is 66. For those born in 1960 or later, it’s 67.
Those born between 1955 and 1959 land on a graduated scale that moves up by two months per birth year, topping out at 66 and 10 months for those born in 1959. Filing without knowing your specific full retirement age means potentially claiming early without even realizing it, and the reduction is applied permanently.
3. Ignoring the Earnings Test While Working
Retirees who claim Social Security before reaching full retirement age and continue working face a benefit reduction if their income exceeds certain thresholds. In 2025, the annual earnings limit for those under full retirement age was $23,400.
Earnings above that trigger a $1 reduction in benefits for every $2 earned over the limit. Those benefits aren’t simply lost forever, as the SSA recalculates them upward at full retirement age, but the temporary loss can create real cash-flow problems and confuse planning.
4. Overlooking Spousal Benefits
The spousal benefit allows a person to collect up to 50 percent of their spouse’s full retirement age benefit, which in some situations is more than what they’d receive on their own record. Many couples overlook this entirely or fail to coordinate their claiming strategies.
A lower-earning spouse who claims early can permanently reduce both their own benefit and their spousal benefit. Coordinating who claims when, particularly in households with a significant income gap between spouses, can add up to meaningful money over time.
5. Forgetting About Survivor Benefits
When one spouse dies, the surviving spouse can claim the higher of the two benefits. That makes the higher earner’s claiming decision consequential for both people. If the higher earner claims early at a reduced rate and then dies first, the surviving spouse is stuck with that permanently reduced figure for the rest of their life.
Delaying the higher earner’s claim, even by a few years, can significantly increase the survivor’s lifetime income.
6. Not Accounting for Taxes
Social Security benefits can be taxable, and a lot of retirees are surprised to discover this. Combined income, which is adjusted gross income plus nontaxable interest plus half of Social Security benefits, determines how much of a benefit gets taxed. For single filers, up to 50 percent of benefits may be taxable once combined income exceeds $25,000, and up to 85 percent becomes taxable above $34,000.
For married couples filing jointly, those thresholds are $32,000 and $44,000 respectively. Strategic withdrawals from retirement accounts, Roth conversions before claiming, and careful income planning can reduce the tax bite considerably.
7. Failing to Check Your Earnings Record
Social Security benefits are calculated based on the 35 highest-earning years in a person’s work history. Errors in those records are more common than the SSA would probably like to admit. A missing year, an incorrectly reported wage, or an employer who never properly filed payroll taxes can quietly reduce a benefit without anyone noticing.
The SSA’s online portal at ssa.gov allows anyone to review their earnings record, and it’s worth checking periodically, not just the month before filing.
8. Assuming the Benefit Amount Is Fixed
Benefits are adjusted annually for inflation through cost-of-living adjustments, but the base amount, which is the number used to calculate those adjustments, depends entirely on when a person files. Delaying past full retirement age earns delayed retirement credits of 8 percent per year, up to age 70.
Someone who waits from 67 to 70 increases their benefit by 24 percent permanently. That higher base also means larger COLA adjustments every year going forward.
9. Not Having a Claiming Strategy at All
The biggest mistake might simply be treating Social Security as an afterthought, filing when it feels convenient without running any numbers. There are dozens of online calculators, and financial planners who specialize in retirement income can model different scenarios.
Health, life expectancy, other retirement income sources, and marital status all factor into the optimal claiming age. A few hours of planning before filing can translate to thousands of dollars annually for decades.
