Most retirees make at least one of these errors—and never realize what it’s costing them. Here’s how to spot them, avoid them, and protect every dollar of the benefit you’ve earned.

You spent your entire working life paying into Social Security. Every single paycheck, for every year you worked, a portion of your earnings went into the system. For most Americans, that represents four decades of contributions — and the promise of a guaranteed, inflation-adjusted income stream for the rest of your life.

And yet, study after study finds that the majority of American retirees make at least one significant Social Security claiming decision that permanently reduces their lifetime benefit. Not by a little. By tens of thousands of dollars. In some cases, by well over $100,000 across a full retirement.

The cruel irony is that these mistakes almost never feel like mistakes in the moment. Claiming early feels like getting money sooner. Not coordinating with a spouse feels like simplifying things. Ignoring the earnings test feels like an irrelevant technicality. Each decision seems reasonable in isolation — and each one can cost a retiree a staggering amount of money in the long run.

This article is about making sure that doesn’t happen to you. We’re going to walk through the nine most expensive Social Security mistakes American retirees make — what they are, exactly what they cost, and precisely how to avoid them. Some of these you may have already navigated correctly. Others might stop you cold. Either way, you deserve to know all of them.

The stakes are real: the difference between the worst and best Social Security claiming decision for an average earner can exceed $150,000 in lifetime benefits. For couples, the gap between optimal and suboptimal claiming strategies can top $250,000. These are not edge cases — they are the result of common decisions made without complete information.

Mistake #1: Claiming at 62 Without Running the Numbers

This is the most common — and often the most expensive — Social Security mistake American retirees make. The moment you turn 62, you become eligible to claim your Social Security retirement benefit. And every year, millions of Americans do exactly that, drawn by the appeal of getting money in hand as soon as possible.

What most of those retirees don’t fully appreciate at the moment of claiming is that taking benefits at 62 results in a permanent, irrevocable reduction of up to 30% compared to waiting until your Full Retirement Age (FRA) — which is 66 or 67 depending on your birth year. Not a temporary reduction. A permanent one, locked in for the rest of your life and adjusted upward from that reduced base for inflation each year.

Let’s make this concrete. If your full retirement benefit at age 67 would be $2,500 per month, claiming at 62 reduces that to approximately $1,750 per month — a $750 monthly difference. Over a 25-year retirement, that gap compounds to over $225,000 in lost lifetime income, before accounting for COLA adjustments.

Claiming early can make sense in specific circumstances — poor health with a shortened life expectancy, urgent financial need with no alternatives, or a spouse’s situation that makes early claiming strategically optimal. But the decision should always be the result of a deliberate break-even analysis, not impatience or a reflexive assumption that getting money sooner is always better.

 Potential cost: Up to $225,000+ in lifetime benefits for an average earner claiming at 62 vs. 67

The Fix: Use SSA.gov’s Retirement Estimator to see your exact benefit at every claiming age. Calculate your personal break-even point — the age at which delayed claiming overtakes early claiming in total lifetime value. For most retirees in average or good health, that break-even falls between ages 78 and 82.

Mistake #2: Not Waiting Until 70 If You Can Afford To

On the other end of the spectrum, retirees who claim at their Full Retirement Age rather than waiting until 70 also leave significant money on the table — albeit a more forgivable amount than those who claim at 62.

For every year you delay claiming past your Full Retirement Age, your benefit grows by 8% per year — guaranteed, regardless of market conditions. This Delayed Retirement Credit accumulates until age 70, after which no additional credit accrues. Waiting from 67 to 70 increases your monthly benefit by 24% permanently.

That 8% annual guaranteed return is one of the best risk-free returns available anywhere in the financial world. Treasury bonds don’t offer it. CDs don’t offer it. Annuities don’t guarantee it. And unlike investment returns, it is completely immune to market volatility, inflation-adjusted for life, and guaranteed by the federal government.

Using the same example: if your benefit at 67 is $2,500 per month, waiting until 70 raises it to approximately $3,100 per month — a $600 monthly difference that compounds over a long retirement into well over $100,000 in additional lifetime income for those who live into their mid-eighties and beyond.

Waiting until 70 requires the financial resources to bridge the gap — either through retirement savings, a spouse’s income, or part-time work. It isn’t right for everyone. But for retirees in good health with adequate savings, it is frequently the single most valuable financial decision they can make.

Potential cost: $100,000–$180,000+ in lifetime benefits for an average earner claiming at FRA vs. waiting to 70

The Fix: If you can cover your expenses without Social Security until 70 — through savings, a spouse’s income, or part-time work — model the delay seriously with a certified financial planner (CFP). The math is compelling for anyone in reasonable health with a family history of longevity.

Mistake #3: Spouses Claiming Without Coordinating

For married couples, Social Security claiming is not two separate individual decisions — it is one joint strategic decision that should be optimised for the household as a whole. Failing to coordinate is one of the most expensive mistakes a couple can make, and it is almost universally the result of simply not knowing the rules.

Here is the core dynamic: when the higher-earning spouse delays their claim, they are not just increasing their own benefit. They are also increasing the survivor benefit — the amount the surviving spouse will receive for the rest of their life after the first spouse passes away.

Because women statistically outlive men, and because the surviving spouse keeps only the larger of the two benefits, maximising the higher earner’s benefit through delay has an outsized lifetime value for the couple.

A common suboptimal strategy: both spouses claim at 62 simultaneously because it feels symmetrical and simple. A far better strategy for most couples: the lower-earning spouse claims early to provide household income during the gap, while the higher-earning spouse delays to 70 to maximise the eventual survivor benefit. This approach can add $200,000 or more in lifetime household income for couples where there is a significant earnings gap between spouses.

Key rule: The surviving spouse receives the higher of the two benefits — not both. This makes maximising the higher earner’s benefit through delay one of the most powerful long-term financial moves a couple can make together, particularly given that one spouse is likely to live well into their eighties or nineties.

Potential cost: $100,000–$250,000 in lifetime household income lost through uncoordinated spousal claiming

The Fix: Before either spouse files, model multiple claiming scenarios together — ideally with a fee-only certified financial planner who uses Social Security optimisation software. The ‘right’ answer depends on both spouses’ ages, health, benefit amounts, and financial resources, and it almost never involves both claiming at the same time.

Mistake #4: Ignoring the Spousal Benefit — Even After Divorce

Millions of Americans are entitled to a Social Security spousal benefit that they never claim — simply because they don’t know it exists or don’t realise they qualify.
If you are married, you may be entitled to a spousal benefit equal to up to 50% of your spouse’s Full Retirement Age benefit — even if you worked very little or not at all during your marriage. This benefit is claimed in addition to, or instead of, your own earned benefit, whichever is higher.

Here is the part that surprises most people: divorced spouses can also claim spousal benefits — provided the marriage lasted at least ten years, you are currently unmarried, and you are at least 62 years old. Your ex-spouse does not need to have filed yet (as long as you have been divorced for at least two years), and claiming your spousal benefit has absolutely no effect on their benefit.

Widows and widowers have additional options through survivor benefits — potentially claiming survivor benefits early while letting their own earned benefit grow, then switching to their own higher benefit at 70. This strategy, when available, can add tens of thousands of dollars in lifetime income and is one of the most underutilised Social Security planning tools available.

Potential cost: $50,000–$150,000+ in unclaimed spousal or survivor benefits over a full retirement

The Fix: Call SSA at 1-800-772-1213 or log in to ssa.gov to check your full benefit options — including spousal and survivor entitlements. If you were married for 10+ years and are now divorced, check whether you qualify for an ex-spousal benefit. Many people discover they are entitled to significantly more than they thought.

Mistake #5: Working While Collecting Before Full Retirement Age

This is one of the most misunderstood rules in the entire Social Security system — and violating it costs thousands of retirees real money every year.

If you claim Social Security before your Full Retirement Age and continue working, the SSA applies an earnings test that temporarily withholds a portion of your benefit if your earned income exceeds certain thresholds. In 2026, if you are below FRA for the full year, SSA withholds $1 in benefits for every $2 you earn above $22,320. In the year you reach FRA, the threshold increases and the reduction rate drops to $1 for every $3 above a higher limit.

Importantly, the withheld benefits are not lost forever — the SSA recalculates your benefit at FRA and gives you credit for the months your benefit was withheld, slightly increasing your future monthly payment. But the cash flow disruption during the withholding period can be significant and is often a complete surprise to retirees who assumed they could claim early and keep working without consequence.

The bigger mistake is the one that often precedes this one: claiming early in the first place when you are still working, usually because the retiree assumed they could supplement a reduced benefit with continued earnings. In most cases, if you plan to keep working, delaying your claim is the better financial decision.

Potential cost: Thousands per year in temporarily withheld benefits — plus the permanent cost of early claiming

The Fix: If you plan to continue working after retirement, strongly consider delaying your Social Security claim until at least your Full Retirement Age. If you have already claimed early and are still working, understand the earnings thresholds and plan your income accordingly. The SSA’s earnings test calculator at ssa.gov can show you exactly how much, if any, would be withheld based on your projected income.

Mistake #6: Not Accounting for Taxes on Your Benefits

Social Security benefits are taxable. This surprises a remarkable number of retirees — particularly those who remember being told their benefits would be “tax-free.” That was never fully accurate, and for most retirees today, a significant portion of their benefit is subject to federal income tax.

The threshold is based on your “combined income” — a formula that adds your adjusted gross income, non-taxable interest, and half of your annual Social Security benefit. If that combined figure exceeds $25,000 for single filers or $32,000 for married couples filing jointly, up to 50% of your benefit becomes taxable. Above $34,000 single or $44,000 married, up to 85% of your benefit is taxable.

These thresholds have never been adjusted for inflation since they were set in 1984, which means more retirees fall into the taxable zone every single year — even those with modest incomes. For a retiree with a $2,000 monthly Social Security benefit, paying income tax on 85% of that at a 22% marginal rate costs over $4,400 per year — money that could have been preserved with proactive tax planning.

Strategic tools to reduce Social Security taxation include: carefully managing IRA and 401(k) withdrawal amounts to stay below thresholds, using Roth conversions in lower-income years to reduce future taxable distributions, and considering the timing of capital gains realisation. This is precisely the kind of multi-year tax strategy a certified financial planner or tax-aware retirement advisor can model for your specific situation.

State taxes on Social Security: most states do not tax Social Security benefits — but 12 states do, including Colorado, Connecticut, Kansas, Minnesota, Missouri, Montana, Nebraska, New Mexico, Rhode Island, Utah, Vermont, and West Virginia. If you live in one of these states or plan to retire there, factor state Social Security taxation into your overall retirement income planning.

Potential cost: $3,000–$8,000+ per year in unnecessary taxes for retirees who don’t plan around the combined income thresholds

The Fix: Work with a tax-aware certified financial planner (CFP) or CPA to model your retirement income specifically around Social Security taxation thresholds. Strategic withdrawal sequencing, Roth conversion planning, and capital gains timing can meaningfully reduce — or in some cases eliminate — the tax on your Social Security benefit.

Mistake #7: Forgetting to Check Your Earnings Record for Errors

Your Social Security benefit is calculated based on your 35 highest-earning years of work. If your official earnings record at the SSA contains errors — incorrect or missing income from years you worked — your benefit will be permanently lower than it should be.

SSA earnings record errors are more common than most people realise. Employers occasionally fail to properly report earnings. Name changes after marriage or divorce can create record-matching problems. Self-employment income reported incorrectly on tax returns can be missing from your record. Jobs held under different names or Social Security numbers can have gaps.

The Social Security Administration makes it straightforward to check: create a free account at ssa.gov/myaccount and review your full earnings history year by year. Compare it against your own records — W-2s, tax returns, pay stubs — for any years where you believe the figures look wrong.

Errors can be corrected, but only if you catch them. And catching them before you file is significantly easier than correcting them after, which requires documentation and a formal dispute process. Every year of missing income in your 35-year record that goes uncorrected reduces your lifetime benefit permanently.

Potential cost: Varies widely, but a single missing high-income year can reduce lifetime benefits by $10,000–$30,000+

The Fix: Create your my Social Security account at ssa.gov/myaccount and review your complete earnings record today — regardless of how far from retirement you are. Do this every two to three years as a routine check. Errors become harder to document and correct the further back they occurred.

Mistake #8: Missing the Medicare Enrollment Connection

Social Security and Medicare are separate programs, but they are deeply connected — and misunderstanding that connection leads to mistakes that are expensive in two different ways simultaneously.

The most common connection error: many retirees assume that signing up for Social Security automatically enrolls them in Medicare. It does not. If you are not receiving Social Security benefits when you turn 65, you must actively enroll in Medicare during your Initial Enrollment Period — the seven-month window surrounding your 65th birthday — or face permanent late enrollment penalties.

The Part B late enrollment penalty is 10% per year for every 12-month period you were eligible but not enrolled — added to your premium permanently for life. For someone who misses enrollment by two years, that is a 20% permanent premium surcharge on every Medicare Part B payment they make for the rest of their life.

The reverse connection is also important: if you are receiving Social Security benefits when you turn 65, you are automatically enrolled in Medicare Parts A and B.

Your Part B premium will be deducted directly from your Social Security check. If you want to decline Part B — for example, because you have employer coverage — you must actively opt out, or you will be charged premiums for coverage you may not need.

Additionally, higher-income retirees pay more for Medicare through IRMAA surcharges based on their income from two years prior. A large Roth conversion, a home sale, or an unusually high-income year can trigger IRMAA and significantly increase Medicare premiums — a cost that must be factored into any Social Security and retirement income planning conversation.

Potential cost: 10% per year, permanently Part B premium surcharge for each year of delayed Medicare enrollment

The Fix: Mark your 65th birthday on the calendar regardless of when you plan to claim Social Security. If you are not on Social Security yet, you must actively enroll in Medicare. Contact SSA at 1-800-772-1213 or enroll at medicare.gov three months before your 65th birthday to avoid any gap or penalty.

Mistake #9: Making the Decision Without Professional Guidance

This is the mistake that underlies all the others. Social Security is one of the most complex benefit systems in the world — with rules governing spousal benefits, survivor benefits, earnings tests, taxation, Medicare coordination, and government pension offsets that interact with each other in ways that are genuinely difficult to navigate without expertise.

And yet, the majority of American retirees make their Social Security claiming decision without ever consulting a financial advisor who specialises in retirement income planning. They rely on general articles, conversations with friends who faced different circumstances, or SSA representatives who are trained to explain the rules but not to provide personalised financial advice.

A fee-only certified financial planner (CFP) with retirement income expertise can model dozens of claiming scenarios for your specific situation — your age, your spouse’s age, both earnings histories, your health, your other income sources, your tax situation, and your long-term care outlook — and identify the strategy that genuinely maximises your lifetime household income. The cost of that analysis is typically $500–$2,000. The value it produces in optimised Social Security income is routinely ten to fifty times that amount.

There are also excellent free resources: SSA.gov’s own benefit calculators, the AARP Social Security Benefits Calculator, and OpenSocialSecurity.com — a free, highly regarded tool built by a financial planner that models optimal claiming strategies for individuals and couples based on their specific benefit amounts and ages.

Potential cost: The cost of not getting advice can easily exceed $50,000–$150,000 in suboptimal lifetime benefits

The Fix: Before filing for Social Security — ideally two to three years before your planned claiming date — consult a fee-only CFP who specialises in retirement income planning. Use free tools like OpenSocialSecurity.com and SSA.gov’s calculators to model scenarios yourself first, then validate your conclusions with professional guidance.

The $100,000 Scorecard: All 9 Mistakes at a Glance

Here is a quick reference summary of every mistake covered in this article — and the approximate cost of each one if left uncorrected over a full retirement:

Mistake #1: Claiming at 62 without analysis
Potential cost: $150,000–$225,000+ in reduced lifetime benefits

Mistake #2: Claiming at FRA instead of waiting to 70
Potential cost: $100,000–$180,000+ in foregone delayed credits

Mistake #3: Spouses claiming without coordinating
Potential cost: $100,000–$250,000+ in household lifetime income

Mistake #4: Missing spousal, ex-spousal, or survivor benefits
Potential cost: $50,000–$150,000+ in unclaimed entitlements

Mistake #5: Working while collecting before FRA
Potential cost: Thousands per year in withheld benefits

Mistake #6: Not planning around Social Security taxation
Potential cost: $3,000–$8,000+ per year in unnecessary taxes

Mistake #7: Never checking your SSA earnings record
Potential cost: $10,000–$30,000+ per missing high-income year

Mistake #8: Misunderstanding the Medicare connection
Potential cost: 10% permanent Part B premium surcharge per year missed

Mistake #9: Deciding without professional guidance
Potential cost: $50,000–$150,000+ in suboptimal lifetime benefits

Your Social Security Benefit Is Too Valuable to Leave to Chance

Social Security is, for most American retirees, the only source of income they will receive for the rest of their lives that is guaranteed, inflation-adjusted, and impossible to outlive. It is the bedrock of retirement financial security for tens of millions of families. It deserves to be treated with the same care and strategic attention as any other major financial decision you make.

The mistakes in this article are not exotic edge cases. They are the decisions that real retirees — people with good intentions, reasonable intelligence, and no desire to leave money on the table — make every single year, simply because no one gave them the complete picture before they filed.

Now you have the complete picture. Use it.

Check your earnings record at ssa.gov today. Model your claiming scenarios at OpenSocialSecurity.com. Coordinate with your spouse before either of you files a single form. And sit down with a fee-only certified financial planner who specialises in retirement income — not to be told what to do, but to make sure the most important income decision of your retirement is made with the full information it deserves.

You earned every dollar of this benefit. Make sure you collect every dollar of it.