Consider a hypothetical couple who did nearly everything right. They saved consistently for thirty years, maxed out their 401(k)s, stayed diversified, and retired at 63 and 65 with $1.8 million. By most measures, they were ready.
The first year went smoothly. Normal withdrawals, familiar lifestyle, no surprises.
Then the market dropped 28% in year two. Their portfolio shrank to roughly $1.3 million while they were still drawing from it. Healthcare costs jumped the same year when one partner needed specialist care Medicare didn’t fully cover. By year seven, inflation had averaged 4.5% annually. The same groceries, the same utilities, the same prescriptions: all measurably more expensive. The purchasing power they had planned around had eroded quietly and steadily.
The number was right. The plan was incomplete.
The couple was financially responsible and well-prepared. The risks that disrupted their retirement are not exotic or unpredictable. They are the five most common categories of financial risk in retirement, and they interact with each other in ways that can stress even a well-funded portfolio. Understanding what they are, why they matter specifically in retirement, and how they compound together is the foundation of retirement income planning.
This guide covers each of the five risks: longevity risk, sequence of returns risk, inflation risk, healthcare cost risk, and withdrawal rate / portfolio depletion risk. It also addresses two secondary risks that deserve a mention, and it explains how they tend to amplify each other when they arrive together. For readers who have already seen one of these topics covered in depth, each section includes a link to the relevant Lifeworks guide.
Why Retirement Risk Is Different From Accumulation Risk
For most of your working life, financial risk has a partial remedy: time. If markets fall 40% in 2002, your contributions keep coming, prices are cheap, and in a decade you are likely better positioned than if the crash had never happened. Accumulation is forgiving.
Distribution is not. When you stop working and start drawing from a portfolio, two things change fundamentally.
The first is that the paycheck disappears. In accumulation, a bad year is a buying opportunity. In distribution, a bad year means selling assets at a loss to fund your living expenses. There is no refill mechanism. Once you sell, those shares stop compounding.
The second change is that sequence matters in a way it didn’t before. Robert Merton, the Nobel Prize–winning economist, captured the problem precisely: “Investment value and asset volatility are simply the wrong measures if your goal is to obtain a particular future income.” (Merton 2014, 1403) A 30-year average return of 7% is meaningful to someone in accumulation. For a retiree who needs income next month, the sequence in which those returns arrive can determine whether the portfolio lasts.
These two shifts (the absence of new money and the importance of order) mean that retirement risk has to be analyzed differently from accumulation risk. The question is no longer “what is my expected return?” It is “what is the probability that my assets fund my income over the full span of my retirement?”
Five distinct categories of risk determine the answer.
Longevity Risk: The Risk of Outliving Your Assets
Longevity risk is the risk that you live longer than your financial plan assumed.
The scale of the miscalculation surprises most people. Traditional retirement income models were built when life expectancy at age 65 was 12 to 15 years. For the average 65-year-old couple today, the Society of Actuaries estimates there is approximately a 50% chance that at least one partner survives to age 90. (Society of Actuaries 2023) A 30-year retirement is not an outlier scenario. It is the realistic planning horizon for a significant share of today’s retirees.
That math creates a compounding problem. Every other retirement risk gets more expensive when it has more years to compound. A 3% annual inflation rate is a modest headwind over 10 years; over 30 years it cuts purchasing power roughly in half. Sequence of returns risk is most damaging in the first few years of retirement. The longer the retirement, the more of those critical early years fall within the risk window. Healthcare costs tend to rise with age, concentrating the largest potential expenses at the end of a long retirement.
Longevity risk does not operate in isolation. It is the multiplier that makes every other risk on this list more expensive.
Planning for a long retirement means running financial projections out to age 90 or 95 rather than age 85. A strategy that works for 15 years may not hold up over 30. And a plan that draws the portfolio down to zero on a fixed schedule is not designed for the retirement most people are likely to have.
One note on framing: longevity statistics reflect population-level actuarial probabilities, not individual predictions. Your personal health history, family history, and lifestyle significantly affect your individual outlook. But in the absence of specific information pointing the other way, erring toward a longer planning horizon is generally the prudent approach.
Sequence of Returns Risk: When Markets Fall at the Wrong Time
Sequence of returns risk is the risk that a major market decline in the early years of retirement permanently impairs the portfolio, even if long-term average returns turn out to be perfectly normal.
Two retirees can start with identical portfolios, make identical withdrawals, and experience identical 20-year average returns. If one of them retired into a bear market and the other retired into a bull market, they will end up in vastly different financial positions. The retiree who got the bad years early sold more shares at lower prices to meet the same withdrawal needs. Those shares are gone. They cannot participate in the recovery. The retiree who got the good years first built a larger base that later declines couldn’t erode as severely.
Research from Dimensional Fund Advisors6 puts numbers on this dynamic. Under a poor-early-returns scenario, a wealth-focused (WF-50%) portfolio showed a failure rate of approximately 33% by age 85; roughly one in three simulation runs ran out of money. An income-focused portfolio designed around liability-driven principles showed a failure rate of approximately 1.2% to 3% under the same conditions. (Pellerin 2021b; based on computer simulation, 10,000 runs; results are sensitive to modeling assumptions and are not a guarantee of future outcomes.)
The gap between those numbers is not primarily driven by average returns. It is driven by how each portfolio is structured to handle early-retirement withdrawals during periods of market stress.
Sequence risk is why the year you retire matters, and why a two-year bear market at the start of retirement is categorically different from the same bear market in year fifteen. By year fifteen, withdrawals have been smaller relative to a larger base, and the compounding math has had time to build a cushion.
Inflation Risk: The Silent Erosion of Purchasing Power
Inflation risk is the risk that the purchasing power of your retirement income declines over time, so the same dollar amount buys less each year.
Over a long retirement, even modest inflation compounds into a meaningful reduction in real income. At 3% per year, the purchasing power of a fixed dollar amount falls by about 26% over 10 years and by roughly 50% over 24 years. A retiree with $80,000 per year in income at age 65 has the equivalent of approximately $55,000 in real terms by age 80, assuming 3% average inflation and no upward adjustment to income. Over a 30-year retirement, the erosion is more severe.
Healthcare inflation amplifies the problem. Medical care costs for retirees have historically risen faster than the general Consumer Price Index measured by the Bureau of Labor Statistics. Retirees allocate a significantly higher share of spending to healthcare than younger households, which means their effective personal inflation rate tends to exceed the headline CPI figure. A Social Security cost-of-living adjustment pegged to general CPI may not keep pace with the actual cost increases a retiree experiences.
Dimensional Fund Advisors’ stress-testing research found that an unexpected increase in inflation raises the failure rate of a conventional wealth-focused retirement allocation from 5.7% to 8.4%. An income-focused allocation designed around liability-driven principles showed a failure rate of 0.1% under the same inflation shock scenario. (Pellerin 2021b; simulation-based; results sensitive to modeling assumptions.)
A portfolio holding mostly nominal bonds may look stable in asset terms while quietly losing ground in income terms. That is the measurement problem Merton identified.
Healthcare Cost Risk: The Wildcard No One Fully Plans For
Healthcare cost risk is related to inflation risk but distinct in an important way. The inflation risk section addressed slow, compounding erosion of purchasing power. Healthcare cost risk is a different problem. Healthcare spending in retirement is structurally unpredictable in ways that other spending categories are not, driven by diagnoses, coverage gaps, premium surcharges, and the potential need for long-term care.
Medicare covers many medical expenses in retirement, but not all of them. Traditional Medicare (Parts A and B) has deductibles and copays, and it has no annual out-of-pocket maximum. It does not cover long-term care (custodial care in a nursing home or assisted living facility), which is among the largest potential healthcare expenses a retiree can face. Dental, vision, and hearing are also not covered under traditional Medicare, though some Medicare Advantage plans include limited coverage for those services.
For retirees with higher incomes, IRMAA surcharges add another layer of complexity. Medicare Part B and Part D premiums are income-adjusted, meaning retirees with modified adjusted gross income above certain thresholds pay significantly higher premiums. Critically, IRMAA premiums are based on MAGI from two years prior — so a large Roth conversion, required minimum distribution, or the sale of a business or property in 2026 won’t affect current Medicare premiums; it will affect 2028 premiums. This lag matters enormously for planning: the income decisions you make today are setting your Medicare costs two years from now. Sometimes this is a temporary one-year spike; sometimes it becomes a sustained increase depending on income patterns.
HealthView Services estimates that a healthy 65-year-old couple may need approximately $315,000 to $400,000 over the course of retirement to cover healthcare costs. (HealthView Services 2023; for illustrative purposes only; actual costs vary significantly based on individual health status, geographic location, plan choices, and utilization.) That range reflects premiums, out-of-pocket costs, and some long-term care provision, but not all scenarios. For couples where one or both partners eventually need extended long-term care, total costs can be substantially higher.
The planning challenge is that healthcare spending doesn’t follow a predictable curve. It tends to be concentrated in the later years of retirement, when the portfolio has had less time to grow and withdrawals may already have depleted earlier reserves.
Withdrawal Rate Risk: Spending Too Much Too Soon
Portfolio depletion risk is the risk that the rate at which you draw from your retirement savings outpaces the portfolio’s ability to sustain distributions over a full retirement.
The 4% rule (the guideline that a retiree can withdraw 4% of their portfolio annually and have a high probability of not outliving their assets over a 30-year period) emerged from historical research in the mid-1990s. It has been useful as a starting point for retirement income planning. It is not a guarantee, and it was not designed as a one-size prescription. In an environment of longer retirements, higher healthcare costs, and evolving market conditions, many retirement researchers suggest treating 4% as a starting reference rather than a fixed target.
More than the rate itself, the timing of withdrawals matters enormously. Spending significantly more in the first five years of retirement has a disproportionately negative effect on long-term portfolio sustainability, in part because of its interaction with sequence of returns risk. The same excess spending in years 15 to 20 of retirement does far less damage, because the portfolio base has had more time to compound. Early overspending reduces that base, and the compounding effect of the lost growth accumulates over the remaining retirement years.
For many retirees, this isn’t purely a math question. Knowing you can spend confidently without fear of running out is one of the central goals of income planning. Social Security timing adds another dimension to withdrawal rate decisions. The age at which a retiree begins Social Security benefits affects the income stream available to supplement portfolio withdrawals. Some households can reduce portfolio draw-down in early retirement by delaying benefits, allowing the portfolio to compound longer before withdrawals begin. Others find that drawing down assets to fund a delay is itself a form of risk: depleting liquid reserves in exchange for a higher monthly benefit that may or may not be offset by the assets spent to fund the waiting period. Spousal benefit considerations further complicate the calculation for married couples.
Required minimum distributions (RMDs) introduce a related risk in the back half of retirement. Large pre-tax IRA and 401(k) balances force mandatory distributions starting at age 73, or at age 75 if you were born in 1960 or later, which can generate income in excess of actual spending needs, pushing retirees into higher tax brackets and triggering IRMAA surcharges in two years later.
How the Risks Interact
Now that each risk has a name, the harder question is what happens when they arrive together. They often do.
Any one of these risks, taken in isolation, is manageable.
The triple threat that most often disrupts retirement income plans is longevity, inflation, and sequence of returns arriving at once. A retiree who faces an early bear market has to sell assets at depressed prices to fund withdrawals. While the portfolio recovers, inflation steadily reduces what those assets will buy in real terms. Because the retiree may live for 30 years, both dynamics compound over a much longer period than anyone models at the outset.
Dimensional Fund Advisors’ research illustrates the compounding effect on conventional wealth-focused portfolios. In a baseline scenario (normal market conditions, no stress), the failure rate at age 85 was 5.7%. Under poor early-retirement stock returns, that failure rate reached approximately 33%. Under unexpected inflation, it rose to 8.4%. These scenarios are modeled independently, but in real retirements they often overlap. (Pellerin 2021b; simulation-based; results are sensitive to modeling assumptions and are not indicative of future outcomes.) Every dollar the portfolio loses in a down market is a dollar that can no longer compound against inflation for the next 20 years.
Healthcare cost risk adds a wildcard that the other risks don’t share. A major medical event or long-term care need can require a large, sudden draw-down. When that draw-down arrives in the same years as a market decline, the sequence-of-returns damage compounds in ways that are difficult to model in advance.
Five risks, each manageable alone. Together, they compound. A retirement plan that addresses each category in isolation — but not their interaction — is still an incomplete plan.
The useful reframe, drawn from the income-focused planning literature, is to measure risk as the probability that the portfolio fails to fund income over the full retirement horizon rather than as asset volatility. Measured that way, the interaction between risks becomes the central planning problem, not any single category.
The Income Planning Response
The question that follows from understanding these five risks is not “how much do I need to save?” Most serious retirement savers have already answered that question. The harder question is: how do I structure 30 years of income to hold up while longevity risk, sequence risk, inflation, healthcare uncertainty, and withdrawal dynamics are all working at once?
Robert Merton described the core problem in 2014: “Most DC schemes are designed and operated as investment accounts, and communication with savers is framed entirely in terms of assets and returns. Asset value is the metric, growth is the priority, and risk is measured by the volatility of asset values.” (Merton 2014, 1403) The shift into retirement requires a shift in how the problem is framed: from building wealth to funding a multi-decade income stream.
The approach that addresses the risk interaction directly is liability-driven investing (LDI): matching assets to income timelines rather than targeting a single blended return. Instead of asking “what return does this portfolio need to generate?” the question becomes “which assets fund income in years 1–3, which fund years 4–10, and which can stay invested long enough to address longevity and inflation?”
The Life-Driven Investing™ framework that guides Lifeworks’ planning approach organizes retirement assets across three tranches matched to income timelines:
- Safe tranche (years 1–3): Cash, money market accounts, T-bills, short-term CDs. No direct market exposure; these instruments carry inflation risk, and their real purchasing power may decline over time. This is where income comes from now. Because withdrawals draw from this tranche rather than from the invested portfolio, a market decline in year one has no direct effect on near-term income. That is how sequence of returns risk is structurally addressed.
- Income tranche (years 4–10): Bond ladders, structured notes, hedged equity (collars, protective puts). This tranche replenishes the Safe tranche as withdrawals draw it down, extending the buffer before any Growth tranche assets need to be liquidated.
- Growth tranche (years 10+): Equities and growth assets. This portion of the portfolio has a decade or more to compound before it is needed. That time horizon makes it appropriate to carry market risk, and the long-term growth potential of this tranche is what addresses both longevity risk (the portfolio may need to last 30 years) and inflation risk (growth assets have historically provided returns above inflation over long horizons, though past performance is not indicative of future results).
The tranche structure also enables more deliberate decisions about Social Security timing, Roth conversions, and RMD management, because the income sequence is planned rather than reactive.
This is a planning framework, not a performance claim. Each tranche carries its own risks: cash is subject to inflation erosion; bond ladders carry interest rate risk and credit risk; hedged equity strategies involve option-related costs and may limit upside; growth assets are subject to market risk and can decline in value. The goal of the structure is not to eliminate risk but to match risk exposure to the time horizon when each dollar is needed.
Common Questions About Retirement Risk
What is the biggest risk in retirement?
There is no single biggest risk. They interact. Longevity risk may be the most foundational, because a longer retirement gives all other risks more time to compound. A 30-year planning horizon is realistic for many of today’s 65-year-old couples, according to Society of Actuaries data, and planning for that horizon changes the significance of every other category.
What is sequence of returns risk?
Sequence of returns risk is the risk that a market decline in the early years of retirement permanently damages the portfolio’s ability to fund income, even if long-term average returns eventually match expectations. Because retirees are drawing from the portfolio rather than contributing to it, bad years early force the sale of assets at low prices, reducing the shares available to participate in recovery. The order of returns matters as much as the average.
How does inflation affect retirement income?
Inflation erodes the purchasing power of fixed or slowly growing income sources over time. At 3% per year, purchasing power declines roughly 50% over 24 years. For retirees, healthcare costs tend to rise faster than general inflation, which means the effective personal inflation rate is often higher than the headline Consumer Price Index. A retirement plan that does not account for inflation explicitly may leave a retiree with adequate nominal income but inadequate real purchasing power in later years.
What is longevity risk?
Longevity risk is the risk of outliving your financial assets. Most people underestimate their own life expectancy. The Society of Actuaries estimates that for a healthy 65-year-old couple, there is approximately a 50% probability that at least one partner survives to age 90. Planning for a 25-year retirement when a 30-year retirement is likely creates a meaningful funding gap.
How much will healthcare cost in retirement?
Healthcare costs are among the most difficult retirement expenses to forecast because they depend heavily on individual health, coverage decisions, geographic location, and whether long-term care is ever needed. HealthView Services estimated in 2023 that a healthy 65-year-old couple may need $315,000 to $400,000 over the course of retirement for healthcare expenses (for illustrative purposes; actual costs vary considerably). Medicare covers many expenses but not all, and does not cover long-term care.
How can I protect my retirement portfolio from market downturns?
No strategy eliminates market risk entirely. One principle that may help: structuring near-term income draws from assets that aren’t subject to market volatility, so that a market decline doesn’t force the sale of equities at a loss to fund living expenses. The tradeoff is that lower-risk assets typically grow more slowly, which affects long-term purchasing power. Every structural choice involves a tradeoff, which is why retirement income planning is situation-specific.
What is a sustainable withdrawal rate in retirement?
There is no universal answer. The 4% guideline is a reasonable starting reference based on historical return data, but it depends on the return environment, the retiree’s time horizon, healthcare cost trajectory, other income sources, and the portfolio’s structure. Both higher and lower withdrawal rates may be appropriate depending on individual circumstances. A retirement income specialist can help model sustainable rates for a specific situation.
Key Takeaway
The retirees who run into trouble aren’t usually the ones who failed to save enough. More often, they are the ones who treated retirement as a savings problem rather than an income problem, who accumulated well but didn’t plan for how the five categories of risk would interact once the paycheck stopped.
Understanding these risks (longevity, sequence of returns, inflation, healthcare costs, and withdrawal rate) and how they compound together is the foundation of building an income plan that holds up over 30 years.
If you’d like to stress-test your retirement plan against each of these risk categories, consider speaking with a retirement income specialist.
Sources
- Bureau of Labor Statistics (BLS). 2024. “Consumer Price Index — Medical Care Components.” U.S. Department of Labor.
- Employee Benefit Research Institute (EBRI). 2024. “2024 Retirement Confidence Survey.” EBRI Issue Brief no. 604 (April 2024).
- HealthView Services. 2023. “2023 Retirement Healthcare Costs Data Report.” HealthView Services.
- Merton, Robert C. 2014. “The Crisis in Retirement Planning.” Harvard Business Review 92, no. 7/8 (July–August 2014): 1401–1408.
- Pellerin, Mathieu. 2021a. “Researching Retirement: Myths and Realities About Asset Allocations.” Dimensional Fund Advisors Research, July 7, 2021.
- Pellerin, Mathieu. 2021b. “Researching Retirement: The Impact of Inflation, Interest Rates, and Market Risks.” Dimensional Fund Advisors Research, July 26, 2021.
- Society of Actuaries (SOA). 2023. “Longevity Risk.” Society of Actuaries Research Report.
Lifeworks is a registered investment advisor. Information presented is for educational purposes only and does not intend to make an offer or solicitation for the sale or purchase of any specific securities, investments, or investment strategies. Investments involve risk and, unless otherwise stated, are not guaranteed. Be sure to first consult with a qualified financial advisor and/or tax professional before implementing any strategy discussed herein. Past performance is not indicative of future performance.
Past performance is not indicative of future results. Any indices referenced are unmanaged and cannot be invested into directly. Index returns do not reflect fees, expenses, or sales charges. All data is believed to be from reliable sources; however, we make no representation as to its completeness or accuracy.