In 1994, a financial planner named William Bengen published a paper that changed how the industry thought about retirement withdrawals. His research, based on historical stock and bond returns going back to 1926, suggested that a retiree could withdraw 4% of their portfolio in the first year of retirement, adjust that amount for inflation each year, and have a high probability of not running out of money over a 30-year retirement.
The "4% rule" was born. And for three decades, it's been the default answer to the question "How much can I safely spend in retirement?"
There's just one problem: it was never meant to be a rule.
Bengen himself has said as much. His research was a starting point, a floor, not a ceiling, and not a substitute for actual planning. And yet somewhere along the way, the financial industry turned a research finding into a retirement planning shortcut. Millions of people are now planning their retirements around a number that was derived from historical data that may not reflect the world they're retiring into.
Here's why the 4% rule falls short, and what a more thoughtful approach looks like.
What the 4% Rule Gets Right
Before we critique it, let's be fair: the 4% rule got some important things right.
It was the first systematic attempt to answer the withdrawal question using actual historical data rather than guesswork. It introduced the concept of sequence-of-returns risk (the danger that early retirement losses can permanently damage a portfolio even if long-term returns are fine). And it gave people a concrete starting point for thinking about how much they need to save.
For a 30-year retirement starting in most historical periods, a 4% initial withdrawal rate has held up reasonably well. That's not nothing.
But "reasonably well in most historical periods" is not the same as "safe for your specific situation, in today's environment, over your specific retirement timeline."
Where It Falls Apart
The 30-year assumption is increasingly outdated. Bengen's research was built around a 30-year retirement. A couple retiring today at 62, with modern healthcare and family longevity, may need their money to last 35 or even 40 years. The probability of a 4% withdrawal rate surviving 40 years is meaningfully lower than surviving 30.
It ignores your actual spending pattern. The 4% rule assumes you withdraw the same inflation-adjusted amount every single year. But that's not how people actually spend in retirement. Most retirees spend more in the early "go-go" years, less in the middle "slow-go" years, and more again in the late years when healthcare costs rise. A rigid, inflation-adjusted withdrawal rate doesn't match this reality.
It doesn't account for guaranteed income. The 4% rule was designed for someone whose only income source is their portfolio. But most retirees have Social Security, and some have pensions. If you have $60,000 per year in guaranteed income and your essential expenses are $80,000, you only need to draw $20,000 from your portfolio, not 4% of whatever your balance is. The rule doesn't know what to do with that.
It treats all portfolios the same. A 60/40 portfolio is not the same as a 100% equity portfolio, which is not the same as a portfolio with a significant allocation to alternative assets. The 4% rule was derived from a specific portfolio construction. Apply it to a different allocation and the math changes.
The current market environment is different. Bengen's research was based on historical returns that included periods of much higher bond yields. In a lower-yield environment, the bond portion of a traditional portfolio generates less income, which affects how long the portfolio lasts under a fixed withdrawal strategy.
What Actually Works
The alternative to the 4% rule isn't a different percentage. It's a different framework entirely.
Start with the income floor. Before you think about portfolio withdrawals at all, establish what guaranteed income you have coming in. Social Security, pensions, annuities. Map that against your essential expenses. The gap between guaranteed income and essential expenses is what your portfolio actually needs to cover. This reframes the withdrawal question entirely.
Use a bucket strategy or dynamic withdrawal approach. Rather than withdrawing a fixed percentage every year regardless of market conditions, a dynamic approach adjusts spending based on portfolio performance. In good years, you might take more. In bad years, you pull back. Research from Vanguard and others suggests that dynamic spending strategies can meaningfully extend portfolio longevity compared to rigid fixed-percentage approaches.
Separate your money by time horizon. The Fiscal House framework we use at Two Waters Wealth divides assets into three buckets: Foundation (safe, liquid assets covering 1 to 2 years of expenses), Walls (income-generating assets covering the medium term), and Roof (long-horizon growth assets). Each bucket has a different job, a different risk profile, and a different time horizon. This structure prevents you from being forced to sell growth assets during a downturn to cover short-term expenses.
Build in flexibility. The most resilient retirement plans are not the ones with the most precise withdrawal rate. They're the ones with the most flexibility. Flexibility to spend more when the market is up. Flexibility to cut discretionary spending when the market is down. Flexibility to adjust the plan as life changes, because life always changes.
Plan for taxes. The 4% rule is a pre-tax concept. It doesn't account for the fact that withdrawals from a traditional IRA or 401(k) are fully taxable, which means your after-tax spending power is lower than the gross withdrawal suggests. A comprehensive withdrawal strategy coordinates which accounts you draw from and in what order to minimize lifetime tax liability.
The Number That Actually Matters
Here's the thing: the 4% rule gives you a number (how much you can withdraw). But the number that actually matters is different: how much do you need to spend to live the life you want?
Start there. Build a realistic picture of your actual retirement expenses, not a generic percentage of pre-retirement income, but a real, category-by-category estimate of what your life will cost. Then build a plan that covers those expenses through a combination of guaranteed income and portfolio withdrawals, with enough flexibility to handle the unexpected.
That's not a rule. It's a plan. And a plan, built around your actual life, will serve you far better than any rule of thumb ever could.
Jason Rindskopf is the founder of Two Waters Wealth Management and creator of the SMART Retirement Blueprint®. He works with high-achieving professionals and couples in the Charlotte, NC area who are within 10 years of retirement or recently retired. If you'd like to talk through your retirement withdrawal strategy and income planning, book a complimentary consultation here.