Biggest Retirement Mistakes

Why This Decision Is Difficult

The retirement mistakes that matter most are invisible until they aren't. A suboptimal withdrawal sequence doesn't produce an immediate consequence — it produces a higher tax bill in year 15. A Social Security claiming decision made at 62 doesn't reveal its full cost until the surviving spouse's income is reduced 20 years later. An outdated beneficiary designation doesn't matter until an estate is being settled under stress. The nature of structural retirement mistakes is that they are low-feedback at the time they're made and high-consequence when they surface.

This creates a dangerous planning environment. The decisions with the longest time horizons and largest lifetime consequences are made in a period of transition and relative uncertainty — often without adequate time for deliberate analysis. Many retirees make the Social Security decision within months of leaving work, without modeling the survivor implications. Many choose a Medicare plan in the first enrollment window based on premium cost alone, without understanding the long-term switching constraints. The compressing timeline tends to force decisions that would benefit from more time.

The underlying problem is that most financial education and planning infrastructure is oriented around accumulation, not distribution. The skills and attention required to build a portfolio over 30 years are different from those required to draw one down intelligently — and the distribution phase often gets far less preparation time despite having equally consequential decisions.

Common Blind Spots

• Claiming Social Security by default rather than by design. Many people claim Social Security when they retire, treating it as an automatic step rather than a decision to model. For married couples, the higher earner's claiming age determines survivor income — making it one of the most consequential decisions in the entire retirement plan.
• No defined withdrawal sequence. Drawing from whichever account is convenient rather than following a tax-optimized sequence can cost significantly more in lifetime taxes. The optimal sequence — which varies by bracket, account mix, and income projections — should be explicit, not improvised.
• Ignoring the RMD horizon. A large pre-tax IRA or 401(k) that was tax-deferred for decades will begin generating mandatory taxable distributions at 73. For people with significant pre-tax balances, these distributions may be larger than expected spending — and the tax cost can be reduced by Roth conversions made years earlier.
• Retiring without a healthcare bridge plan. Employees often have healthcare subsidized by employers for decades and have little awareness of true costs. COBRA, ACA marketplace premiums, and out-of-pocket costs can total $20,000–$40,000 per year for a couple in their early 60s — a number that often comes as a shock.
• Outdated estate documents. Wills and beneficiary designations created in the accumulation years may not reflect current family structure or assets. An ex-spouse named as IRA beneficiary inherits it regardless of what the current will says. Estate documents not reviewed in 5+ years are typically stale in at least one material way.
• Treating Medicare as free or near-free. Part B premiums, Part D costs, Medigap or Advantage premiums, and services Medicare doesn't cover (dental, vision, hearing, long-term care) add up to real money. IRMAA surcharges for higher-income retirees can add thousands more annually. Many retirees budget less than half of their actual healthcare costs.
• No advisor coordination. A financial advisor who doesn't communicate with the CPA doesn't know that a Roth conversion will trigger IRMAA. An estate attorney who doesn't know the retirement account balances creates a beneficiary structure misaligned with the tax plan. Coordination among advisors is where retirement planning either holds together or develops expensive gaps.
• Underestimating the length of retirement. A couple retiring at 62 has a meaningful probability that at least one spouse lives past 90. A plan designed for 20 years may be tested for 30. Longevity risk — the risk of outliving the plan — is the organizing concern of retirement income planning, and it is systematically underweighted by retirees who anchor to average life expectancy rather than planning for the upper tail.

Questions Worth Asking

• Have you modeled all three Social Security claiming scenarios — your age, your spouse's age, and the survivor benefit at each combination? For a married couple, this is a multi-variable optimization, not a simple break-even calculation. A financial planner or Social Security optimization tool should run the full scenario matrix.
• What is your written withdrawal sequence for the first 10 years of retirement? This should specify which account type is drawn first, in what amounts, and under what conditions the sequence would be modified. If the answer is "whatever we need," that is not a plan.
• What are the projected RMDs from your pre-tax accounts at age 73, 75, and 80? The IRS provides RMD tables based on account balances and age. Your CPA or financial planner should be able to model these projections and evaluate whether Roth conversions before 73 would reduce the lifetime tax cost.
• What is your specific healthcare plan from retirement to age 65? Name the coverage source, estimate the monthly cost, and confirm it has been verified as available. A plan that says "figure out healthcare when the time comes" is a meaningful unaddressed risk.
• When were your beneficiary designations last reviewed? List every retirement account, life insurance policy, and transfer-on-death account and confirm the current beneficiary on each is accurate and intentional. This should be done annually.
• Have you stress-tested the retirement plan against living to age 90 or 95? Longevity planning requires modeling spending, healthcare costs, and portfolio performance across a longer horizon than most people assume. The plan should remain solvent in the optimistic scenario, not just the average one.
• Do your financial advisor, CPA, and estate attorney communicate directly with each other? If the answer is no, identify the specific intersections — Roth conversion and tax planning, beneficiary designations and estate structure, income levels and Medicare premiums — and ensure someone is responsible for coordinating across them.
• What does the surviving spouse's financial picture look like? Map out the income, accounts, and expenses the surviving spouse would face. Does the plan work for them independently, or does it depend on both spouses' continuing presence?

What Most People Miss

The most important thing most people miss is that retirement mistakes are front-loaded. The decisions that most affect outcomes over a 25-year retirement are made in the 1-3 years before and immediately after retiring. Social Security timing, account withdrawal sequencing, Medicare plan selection, Roth conversion windows, and estate document review all have their most consequential windows in this period. Waiting until retirement begins to address these areas means several of the best planning windows have already closed.

The second thing most people miss is the distinction between a mistake of omission and a mistake of commission. A wrong investment is a mistake of commission — you did something that didn't work. Most structural retirement mistakes are mistakes of omission — decisions that were never explicitly made, defaults that were never examined, coordinations that were never arranged. The advisor who was never asked to run the RMD projections. The Social Security decision made by default rather than analysis. These omissions are harder to see precisely because nothing was done.

Finally, most people underestimate the degree to which these decisions interact. The Social Security claiming age affects how much needs to be drawn from the portfolio in early retirement, which affects the withdrawal sequence, which affects bracket management, which affects the Roth conversion strategy, which affects future RMDs, which affects Medicare premiums. Optimizing each decision in isolation — without modeling the interactions — produces a plan that looks good on paper and underperforms in practice. The planning work that surfaces these interactions is the planning work most worth doing.