Consider a hypothetical couple (we’ll call them the Hendersons). Over 32 years they did almost everything right. They maxed their 401(k) contributions, reinvested dividends, stayed in the market through downturns, and arrived at retirement with $1.4 million across a mix of accounts. They had worked hard, been patient, and followed the standard accumulation playbook to the letter.
And then came the question nobody had fully prepared them for.
Which account do you draw from first? How much do you take out each month? What happens if the market drops 30% in year two? Do you keep taking withdrawals, or do you wait it out? Who decides? They had spent 32 years optimizing for growth. Nobody had walked them through how to actually pay themselves.
Retirement income planning is a different discipline than retirement savings. The assets are the same. The strategy is not.
The transition from accumulation to distribution is one of the least-discussed challenges in financial planning. For decades, the financial services industry has organized itself around helping people build wealth. The metrics were clear: account balance, rate of return, asset allocation. Growing the number. But as Nobel laureate economist Robert Merton has argued, these are the wrong measures once the goal shifts from wealth accumulation to income generation. “Investment value and asset volatility are simply the wrong measures,” Merton wrote, “if your goal is to obtain a particular future income.” (Merton 2014)
The challenge the Hendersons faced has a name: the decumulation problem. Solving it requires a framework, not just a withdrawal rate.
The Number That Actually Matters: Your Income Gap
Most retirement planning conversations start with “how much do I have?” But the more useful question for income planning is: how much does my portfolio actually need to provide?
The answer depends on two things: what you spend each month, and how much of that spending is already covered by guaranteed income.
Your income gap is the difference between your essential monthly expenses and your guaranteed monthly income. It is the number your portfolio must fund. Everything else in the income architecture flows from this calculation.
Here is how to find it. Start with your essential monthly expenses: housing, food, healthcare premiums, insurance, transportation, utilities. These are the costs that show up reliably every month regardless of what the market does. Leave out discretionary spending for now; you can layer that in separately.
A note on taxes: For this calculation to be accurate, expenses should reflect your after-tax spending needs — what you actually need in hand each month. Withdrawals from traditional IRAs, 401(k)s, and other tax-deferred accounts (including RMDs) are taxed as ordinary income, which means the gross amount you need to withdraw will be higher than the net expense itself. A qualified financial advisor or tax professional can help you model the appropriate tax gross-up for your situation.
Then subtract your guaranteed monthly income — the income you receive regardless of what your portfolio does: Social Security benefits (yours and, if applicable, your spouse’s), pension income, and annuity payments you are already receiving. If you also receive rental income, you may include a conservative portion of it here, though rental income is not fully guaranteed given the potential for vacancies, maintenance costs, and management expenses — so it warrants more careful treatment than Social Security, pension, or annuity income.
What remains is your income gap — the amount your investment portfolio must generate each month to cover your essential spending.
To make the math concrete: consider a couple with $6,000 per month in essential expenses and $4,500 per month in combined Social Security income. Their income gap is $1,500 per month. Now consider a second couple with the same $6,000 in expenses but only $2,500 per month in Social Security. Their income gap is $3,500 per month.
The difference in portfolio burden is more than double. The first couple needs their portfolio to provide $18,000 per year. The second couple needs $42,000 per year, from the same type of assets, exposed to the same market risk. The gap in Social Security income alone translates into a dramatically different set of requirements for how the portfolio must be structured.
This is why decisions about Social Security claiming, pension elections, and annuity purchases are not merely income decisions. They are portfolio allocation decisions. Every dollar of permanent guaranteed income reduces the amount the portfolio must produce, and reduces the risk the portfolio must accept to produce it.
The Three-Bucket Framework
Once you know your income gap, the question becomes how to structure a portfolio to cover it reliably across a retirement that may last 25 to 30 years, through market downturns, rising healthcare costs, and the inevitable uncertainty of what lies ahead.
The three-bucket framework provides that structure. The concept was first formalized by financial planner Harold Evensky in the 1980s, and later popularized by Morningstar’s Christine Benz. The central insight is that not all of your portfolio needs to be invested the same way, because not all of your portfolio needs to do the same job. Matching assets to their time horizon allows each portion of the portfolio to take only the risk appropriate for when it will be needed.
This kind of framework — sometimes called life-driven investing — starts with your income needs, not your portfolio. It asks: what does this money need to do, and when? The answers to those questions determine how each portion should be invested.
The Safe Bucket covers your income gap for approximately the first one to three years of retirement. This money is held in cash equivalents and short-term instruments: money market accounts, short-term CDs, Treasury bills. It carries no meaningful market risk. When equity markets decline 20% or 30%, this money does not move. That stability is the point. The Safe bucket ensures that you never have to sell growth-oriented investments at depressed prices to pay this month’s bills. It is your near-term paycheck, decoupled from short-term market noise.
The Income Bucket covers the income gap for approximately years three through ten. This portion is invested in more conservative, income-generating positions: intermediate bonds, bond ladders, structured income instruments, and income-focused equities. The Income bucket accepts moderate volatility because it has a medium-term time horizon: you won’t need this money for at least three years, which provides time to recover from temporary declines. Its primary job is to replenish the Safe bucket as that bucket is drawn down.
The Growth Bucket holds everything that won’t be needed for at least a decade. This is your equity portfolio, diversified growth-oriented holdings designed to grow over time. Because this money has a ten-plus year runway before it needs to be tapped, it can absorb market cycles. The Growth bucket’s job is to replenish the Income bucket over time and to help protect purchasing power across a potentially 30-year retirement. The long time horizon is what makes the volatility tolerable.
The three buckets work as a system. The Safe bucket pays monthly income. The Income bucket replenishes the Safe bucket as it depletes. The Growth bucket replenishes the Income bucket over time and drives long-term purchasing power. Think of it as a conveyor belt: each bucket feeds the one before it, on a timeline that insulates near-term spending from long-term market volatility.
It is worth noting that researchers have observed that a well-implemented bucket strategy may produce outcomes comparable to a total-return portfolio with disciplined rebalancing. The framework’s primary value is structural and behavioral: it prevents forced selling in down markets and provides clear decision rules for how income is funded at each stage of retirement.
What makes this framework powerful is that the structure is built around your specific income gap, not a generic allocation model. A couple with a $1,500 monthly income gap needs a sharply different bucket configuration than a couple with a $3,500 monthly gap, even if their total portfolio values are identical.
Sizing Your Buckets: It Starts With the Gap
Bucket sizes are calculated from the income gap, not from total expenses. This is the critical distinction. The portfolio only needs to cover what guaranteed income sources do not.
Using the illustrative Henderson example: with a $1,500 per month income gap, the math looks like this.
The Safe bucket covers 36 months (three years) of the income gap: $1,500 × 36 = $54,000.
The Income bucket covers months 37 through 120 (years three through ten): $1,500 × 84 = $126,000.
The Growth bucket holds everything else: $1,400,000 − $54,000 − $126,000 = $1,220,000.
These are illustrative figures. The structure shows something important: when the income gap is relatively small because of strong guaranteed income sources, the vast majority of the portfolio is free to pursue long-term growth. In this example, more than 87% of the portfolio is in the Growth bucket, working with a 10-plus year time horizon.
Now consider how different this looks for the second couple, the ones with the $3,500 monthly income gap.
Safe bucket: $3,500 × 36 = $126,000. Income bucket: $3,500 × 84 = $294,000. Growth bucket: $1,400,000 − $126,000 − $294,000 = $980,000. With the same $1.4 million portfolio and the same expenses, this couple has only 70% in the Growth bucket, with $420,000 tied up in the lower-returning Safe and Income buckets instead of $180,000.
A higher guaranteed income floor does not just improve monthly cash flow. It structurally frees the portfolio to pursue the growth it needs to sustain a long retirement.
No investment strategy eliminates all risk, and these bucket sizes are meant to illustrate the concept, not serve as personalized guidance. The right allocation depends on your actual expenses, your income sources, your tax situation, your health, and your goals.
The Role of Each Income Source
Understanding how each guaranteed income source interacts with the income gap helps explain why the decisions around these sources carry so much weight. These are not independent choices. Each one directly affects how much the portfolio must produce and therefore how the three buckets are sized.
Social Security
Social Security is the most consequential income floor decision most retirees make. The claiming decision is permanent: claiming at 62 reduces benefits by up to 30% compared to full retirement age (FRA); delaying to age 70 increases them by approximately 8% per year beyond FRA (SSA 2026), up to a maximum of approximately $5,181 per month for someone reaching 70 in 2026. The average Social Security retirement benefit in January 2026 was approximately $2,071 per month, illustrating the wide range of outcomes depending on earnings history and claiming age. (SSA 2026)
As Dimensional researcher Mathieu Pellerin has noted, Social Security delay is effectively equivalent to “buying additional amounts of an inflation-indexed annuity backed by the US government,” one that provides a permanent income floor increase, adjusted for inflation, for life (Pellerin 2021a). The decision to delay to 70 versus claiming at 62 can represent a difference of $800 to $1,500 per month or more in permanent income — a reduction in the income gap that compounds for every year of retirement.
For married couples, the claiming strategy has an additional dimension: the higher earner’s benefit will become the survivor benefit after the first death. A spouse delaying to 70 may be building not just their own income floor but a permanent floor for a surviving spouse who could live 10 to 15 additional years.
Individual Social Security benefits vary based on earnings history, claiming age, and year of birth. Consult the SSA’s online tools or a financial advisor for personalized estimates.
Pension Income
For retirees with a defined-benefit pension, the income option versus lump-sum choice is structurally equivalent to a decision about the income gap. Choosing the annuity option reduces the income gap permanently. It becomes guaranteed income that flows alongside Social Security, shrinking the bucket requirements. Taking the lump sum transfers the pension balance to the portfolio, where it must then cover the income gap that the pension would have eliminated.
Neither choice is inherently superior; the right answer depends on health, other income sources, portfolio size, and survivor needs. But the framework makes the trade-off explicit: the lump sum buys flexibility at the cost of a permanent guaranteed floor.
Annuity Income
A purchased income annuity — whether a single premium immediate annuity (SPIA) or a deferred income annuity — functions like a private pension. It reduces the income gap, shrinks the Safe and Income bucket requirements, and potentially frees more of the portfolio for growth. For a retiree with a significant income gap not covered by Social Security or a pension, an annuity may be worth evaluating for the portion of the gap that needs permanent coverage.
Annuities are insurance products with real benefits and real trade-offs that vary widely by product type and insurer. On the benefit side, a properly structured income annuity can provide guaranteed lifetime income regardless of market conditions — income that cannot be outlived. (Note: annuity guarantees are subject to the claims-paying ability of the issuing insurance company.) On the trade-off side: purchasing an annuity typically means forgoing control of the assets used to purchase it, accepting fixed or limited-adjustment payments that may not fully keep pace with inflation, and giving up the ability to leave those assets as a bequest. Consult with a qualified financial professional before making any decision about annuity products.
Rental Income
Rental income can reduce the effective income gap, but it is not guaranteed in the same way as Social Security, pension, or annuity income. Vacancy periods, maintenance costs, and property management expenses make it variable. In practice, it may be reasonable to count a conservative portion of reliable rental income toward the floor calculation while reserving buffer for these variabilities. The more stable and predictable the rental income history, the more confidently it can be incorporated — but it warrants more careful treatment than income sources that carry no operational or vacancy risk.
Part-Time Work
For those who retire in their early to mid-60s and continue some form of part-time work, earned income in the early years of retirement can significantly reduce portfolio drawdown during the period when sequence-of-returns risk is highest. A retiree covering even $1,000 to $2,000 per month in expenses through part-time work in years one through five is effectively supplementing the Safe and Income buckets, giving the Growth bucket time to potentially grow before it needs to begin funding income.
Research on sequence-of-returns risk is clear: large losses in the first three to five years of retirement do disproportionate damage compared to the same losses occurring later. The Safe bucket is the structural defense against forced selling in down markets. Part-time income is its complement. It reduces how much the Safe bucket must supply while the Income and Growth buckets build.
One important caveat: if you claim Social Security benefits before full retirement age and continue working, the Social Security earnings test may temporarily reduce your benefits. In 2026, benefits are reduced by $1 for every $2 earned above $24,480 per year for those under full retirement age. A higher threshold applies in the calendar year you reach FRA ($65,160 in 2026), with a smaller $1-for-$3 reduction on earnings above that amount. Benefits withheld under the earnings test are not lost permanently — they are recredited at full retirement age in the form of a higher monthly benefit going forward — but the near-term cash flow impact is real and worth planning for. (SSA 2026)
RMDs and the Paycheck
After age 73 (or 75 for those born in 1960 or later, under SECURE 2.0), required minimum distributions begin from traditional IRAs and most employer retirement plans. RMDs are calculated annually by dividing the prior December 31 account balance by an IRS life expectancy factor. Failing to take the required amount carries a 25% penalty, reduced to 10% if corrected within two years. (IRS Publication 590-B 2025)
Two notable exceptions worth knowing: Roth IRAs are generally not subject to RMDs during the account owner’s lifetime, which is one reason Roth conversions in your 60s can be a valuable planning tool. Additionally, if you are still actively working and participating in your current employer’s retirement plan, you may be able to delay RMDs from that plan until you retire — provided you are not a 5% or greater owner of the company. Traditional IRAs and accounts from prior employers are not eligible for this work-still exception.
In a retirement income architecture, RMDs are an income source to be planned for, not a problem to be managed around. When RMDs begin, they represent required annual withdrawals from tax-deferred accounts that can be routed directly into the Safe or Income bucket, reducing the need to sell Growth assets for income. A well-designed plan integrates the RMD schedule into the paycheck calendar so that required distributions replenish the near-term buckets rather than accumulating in cash without a plan.
There is also a tax dimension: RMD proceeds land as ordinary income, which can interact with Social Security taxability and Medicare premium calculations. The timing and amount of distributions in your 60s — including potential Roth conversions before RMDs begin — can significantly affect the tax efficiency of your retirement paycheck for decades. This is worth careful planning before age 73 arrives.
For a detailed explanation of how RMDs are calculated and what accounts they apply to, see our guide: Required Minimum Distributions Explained.
Building the Plan
Building a retirement paycheck is a design exercise, not a formula. The income gap, three buckets, and guaranteed income floor give the framework its structure. The right design depends on your specific numbers.
Consider what this exercise reveals about the Hendersons. They arrived at retirement with $1.4 million and a sense that the hard part was behind them. The actual hard part was just beginning: designing a system that could reliably pay them for 30 years through whatever markets bring. With a clear income gap calculation and a well-structured bucket architecture, their $1.4 million is positioned to do that job. Without one, the same $1.4 million is subject to the accumulation-era mistake: measuring success by account value rather than by the income it can produce.
Robert Merton’s framing is useful here. “The only way to avoid a catastrophe,” he wrote, “is for plan participants, professionals, and regulators to shift the mind-set and metrics from asset value to income.” (Merton 2014) The three-bucket framework is one practical expression of that shift.
A few principles worth holding as you think about your own situation:
The income gap is the starting point, not the portfolio. The right bucket structure emerges from your expenses and guaranteed income sources — not from a standard allocation model.
Guaranteed income sources are portfolio allocation decisions. Every dollar of permanent income from Social Security, pension, or annuity reduces your income gap, shrinks your near-term bucket requirements, and frees more assets for growth.
The Safe bucket is not idle cash. It is structural protection against sequence-of-returns risk — the guarantee that you will not be forced to sell growth assets at the wrong time.
RMDs are income, not an interruption. Integrated into the paycheck architecture, required distributions can replenish near-term buckets and reduce the need to sell Growth assets for income.
If you are within five years of retirement, or if you have already retired and are managing withdrawals without a formal architecture, the income gap calculation is the right place to start. It takes the question from “how much can I withdraw?” to “how much does my portfolio need to provide?” That is a better question. And the answer will shape everything that follows.
Consider speaking with a Lifeworks advisor about how this framework applies to your specific income sources and timeline.
Sources
Social Security and Retirement Benefits
- Social Security Administration. “Fast Facts & Figures About Social Security.” ssa.gov.
- Social Security Administration. “Delayed Retirement Credits.” ssa.gov.
Retirement Spending and Income Strategy
- Financial Planning Association. “Spending in Retirement: Determining the Consumption Gap.” financialplanningassociation.org.
- Kitces.com. “Retirement Date Risk: How Sequence of Returns Risk Impacts a Pre-Retirement Accumulator.” kitces.com.
- Fidelity Investments. “How Much Money Do I Need to Retire?” fidelity.com.
Retirement Confidence and Industry Data
- Employee Benefit Research Institute. “Retirement Confidence Survey.” ebri.org.
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. The bucket strategy framework and related examples are illustrative and hypothetical — they do not represent any specific client’s portfolio or actual results. Individual circumstances vary, and no investment strategy eliminates all risk.