How Much Should a One-Person Retirement Plan Hold for Out-of-Pocket Medical Costs?

When you are planning retirement on your own, a medical-cost estimate can feel less like information and more like a warning. A large lifetime number may make you wonder whether you have saved enough. A small annual estimate may feel too fragile when no spouse's income or reserve is available to absorb a difficult year.

The useful question is narrower: how much accessible money should your plan hold for the medical costs that could arrive before your normal cash flow can comfortably absorb them?

Which health costs belong in the reserve?

Start by separating recurring costs from uncertain costs. Premiums for Medicare, Medigap, Medicare Advantage, Part D, an employer retiree plan, or pre-Medicare coverage usually belong in the regular retirement spending plan. They are important, but they are not the same as the reserve.

The reserve is for the costs that vary: deductibles, copays, coinsurance, prescription changes, out-of-network care, and services your coverage excludes or limits. Dental work, glasses, hearing care, and other uncovered services can create meaningful bills even when your medical insurance is working as designed.¹

Your coverage determines the outer edge of that exposure. Original Medicare has no annual out-of-pocket limit unless other coverage provides one, while Medicare Advantage plans have annual limits for covered Part A and Part B services.² Neither figure, by itself, captures every prescription, dental, vision, hearing, or noncovered expense.

What are you trading when you choose a reserve?

A larger reserve may reduce the chance that a medical bill forces a poorly timed investment sale or disrupts ordinary spending. But every dollar held in immediate liquidity is a dollar not serving another purpose. The right amount is not the largest imaginable bill. It is the amount that makes a difficult but plausible year manageable within the rest of your plan.

This staged structure makes the tradeoff visible. Immediate liquidity covers the first layer of uncertainty; the broader portfolio remains the backstop for a rare, larger event. A widely cited lifetime estimate can help test the long-term plan, but it is not a prescription for how much cash to hold now. Fidelity's 2026 estimate for an average 65-year-old retiree is $185,500, and its methodology notes that actual needs vary with health, location, and longevity.³

Dovetail Principle: The Numbers Should Clarify the Decision, Not Promise the Future

A reserve amount should help you decide what to keep accessible now. It should not pretend to predict every diagnosis, treatment, premium increase, or year of life. The strongest number is one tied to your coverage and your plan's ability to respond—not a generalized lifetime average.

How can you set a practical starting range?

Begin with your own recent spending, not a national average. Add the annual premiums already in your budget, then list what you actually paid for deductibles, copays, prescriptions, dental care, vision care, and other services over the last two or three years. Identify which expenses were ordinary and which represented a higher-use year.

Next, read the current plan documents. Note the medical deductible, prescription deductible, copay and coinsurance structure, network rules, and applicable out-of-pocket maximums. In 2026, covered Part D drug spending reaches catastrophic coverage after $2,100 of out-of-pocket spending, but prescriptions not covered by the plan may not receive the same protection.⁴

Then add a separate allowance for reasonably foreseeable uncovered care. Dental, hearing, and vision spending is uneven: many people spend little in a given year, while a smaller group experiences much larger bills.⁵ Known prescription risks, planned dental work, or a preference for providers outside your network can justify a higher working reserve.

Finally, decide how much variation your regular cash flow can absorb. Someone with pension income well above recurring expenses may need less separate cash than someone whose spending already draws fully from the portfolio. Your comfort with uncertainty matters too, as long as the added reserve does not quietly crowd out other priorities.

When should the reserve change?

Give the reserve a replenishment rule. If you use it, restore it from the next planned portfolio distribution, surplus cash flow, or another designated source rather than waiting for the account to feel uncomfortably low. Review the target annually and whenever coverage, prescriptions, health use, income, or your tolerance for disruption changes.

An HSA can be one source of medical funding when available. Qualified withdrawals are generally tax-free, and the balance can remain available across years; Medicare enrollment generally ends eligibility to contribute, but it does not prevent qualified withdrawals.⁶ Keep enough of any invested HSA or portfolio reserve in a form that matches when you may need it.

For a one-person retirement plan, the goal is not to prepay a lifetime of health care. It is to hold enough near-term liquidity for your actual coverage, current health use, and preferred margin of safety—and to maintain a clear backstop and replenishment policy when costs exceed that first layer.