4% Rule vs. Annuities-New Research Says This Hybrid Retirement Income Plan Wins

New research suggests the 4% rule can leave retirees underspending

The surprise is not that the 4% rule fails to last. It is that, for some retirees, it may be too conservative.

New research says many retirees who rely on this classic guideline could preserve too much of their balance and end up spending less than they reasonably could. In practical terms, that can mean less travel, fewer gifts, and less room to enjoy the money saved over a working life.

Why the 4% rule feels safe-and can still underperform

The 4% rule is simple: withdraw 4% of your portfolio in year one, then adjust that amount for inflation in later years. On a $1 million portfolio, the initial withdrawal would be $40,000. That appeal is straightforward: the approach preserves liquidity and flexibility, and it can reduce the fear of running out of money.

The trade-off is that protecting the balance can become the habit. The researchers argue the 4% approach can still carry significant risk of outliving your assets, while also leaving some retirees with more wealth than they need to fund their spending. The result is not failure on paper; it can be a quieter problem in real life-having money left over but not using it to support a better retirement lifestyle.

The 4% rule is vulnerable to timing and false precision

The bigger weakness is not complexity. It is that the rule sounds more exact than it really is.

In its classic form, the guideline says you can take 4% of the total balance in your first year of retirement and then raise that amount for inflation over a 30-year retirement. But the starting dollar amount depends on your portfolio value on one specific launch day.

The starting-date trap

That matters more than it looks. If retiree A retires with $1 million, the first-year withdrawal is $40,000. If retiree B waits until the portfolio grows to $1.25 million, the starting income becomes $50,000. If retiree C retires after it rises to $1.5 million, the starting income jumps to $60,000.

A short delay in retirement timing can change the default spending level by $10,000 to $20,000, even though the "rule" looks the same on the surface.

Why the formula does not do all the work

People also tend to blur what the 4% rule is actually promising. One idea concerns the chance of leaving money behind; another concerns the chance of running out of money. The two are related, but they are not the same thing.

Real retirement spending also changes year to year. Health, housing, travel, and care needs are not flat, and withdrawals from some accounts can create tax consequences. That means two retirees using the same 4% blueprint can still face very different after-tax income and very different cash needs.

That is why the 4% rule works best as a rule of thumb, not a set-it-and-forget-it spending contract.

A partial annuity plus separately invested money scored best

The cleaner answer is not "spend more" or "buy an annuity." It is to layer income sources.

In the study's setup, a retiree at 65 with $1 million in retirement savings was evaluated under three approaches: follow the 4% withdrawal rule, turn the entire nest egg into a single premium immediate annuity, or use a partial annuity while keeping the rest separately invested. The hybrid approach performed best.

Why the hybrid won

The annuity portion can cover essential bills. The separately invested portion can preserve flexibility for bigger purchases, surprises, and whatever else does not fit into a guaranteed paycheck. That matches the study's broader conclusion: the 4% rule offers the most liquidity, but it can still be too risky for people who are risk-averse, while full annuitization can provide more income at the cost of control.

The researchers describe the sweet spot as partial annuitization-either putting half of savings into an annuity up front or gradually converting assets over time. In plain English, you buy a guaranteed base income and keep part of your wealth accessible.

How Social Security fits in

If delaying Social Security is feasible, the hybrid plan can work even better because the annuity has to fill a smaller expense gap. The point is not to hunt for a perfect withdrawal rate. It is to build a base that lasts and keep flexibility where it matters.

How to use the study without turning it into a slogan

This research works best as a design framework, not a catchphrase.

A practical way to structure retirement income

Start by separating "must-pay" expenses from "nice-to-have" spending. Then ask whether a partial annuity can cover the floor while money kept separately invested preserves liquidity and flexibility. The practical takeaway is simple: guarantee the base, keep control of the rest.

A short checklist

• List fixed costs first, then see whether a guaranteed income stream closes that gap.
• Compare three layouts: rely on a spending rule, annuitize everything, or use a hybrid approach. The research says the sweet spot is basically right smack in the middle.
• Test flexibility. The 4% approach offers the most liquidity and flexibility, while full annuitization can limit access to your money.
• Keep the plan adaptable. The 4% guideline works best as a starting point, not a final answer.