Pension Mortality Drag: The Hidden Cost of Staying in Drawdown

Since the pension freedoms of 2015, annuities have fallen dramatically out of fashion. The ability to stay invested, pass wealth to beneficiaries on death, and retain flexibility over withdrawals has made flexi-access drawdown the default choice for most retirees with meaningful pension pots. This preference is understandable. For many retirees in good health with substantial assets, it is also correct.

But there is a cost to staying in drawdown that rarely appears in the headlines — a cost actuaries call mortality drag. It is not visible on a statement. It does not trigger a charge notice. Yet over a sufficiently long retirement, it can represent a material financial disadvantage compared to annuitisation.

This guide explains what mortality drag is, how it works, at what point it becomes a significant planning consideration, and how partial annuitisation can address it without sacrificing all of drawdown's flexibility benefits.

What Is Mortality Drag?

An annuity, at its core, is a pooled longevity product. When an insurance company sells annuities, it collects premiums from a large pool of retirees. Some die earlier than average; some die later. The insurer uses the funds from those who die early to subsidise the payments to those who live longer than expected. The retirees who live to 95 effectively benefit from the premia paid by those who died at 72.

Actuaries call this subsidy the mortality credit or mortality drag credit. It is the return you receive from the annuity pool by virtue of surviving each year, funded by those who did not. This return is not available to drawdown investors — it exists only within a pooled annuity or similar longevity-pooling structure.

When you stay in drawdown, you manage your own pot of money. You receive investment returns. But you receive no mortality credits. For a young retiree in the early years of drawdown, this matters relatively little — the probability of death in any given year is small, so the mortality credit foregone is modest. As you age and the probability of death in any given year rises, the mortality credit that an annuity would pay becomes progressively larger. The cost of forgoing it — mortality drag — increases with age.

The practical consequence: an older drawdown investor must achieve a higher investment return from their self-managed portfolio, over time, simply to match what an annuity would provide. And because an annuity's income is guaranteed regardless of market conditions, that higher investment return target comes with investment risk as well as longevity risk.

How Mortality Drag Is Quantified

The mortality credit embedded in an annuity in any given year can be approximated using the probability of death for someone of that age (derived from actuarial mortality tables) and the annuity rate available at that age.

A very rough illustration (the numbers here are illustrative and will differ from live market rates):

• A 65-year-old male might face an annual mortality probability of approximately 1.0–1.2%
• At 75, this might be approximately 2.5–3.0%
• At 85, this might be approximately 6.0–7.0%

For each year survived, the annuity pool effectively credits the survivor with a proportion of the capital contributed by those who died that year. This credit compounds over time. At 65, it is small enough that a moderate investment return from drawdown can comfortably exceed it. At 80 or 85, the mortality credit becomes large enough that a drawdown portfolio would need to generate substantial net-of-charges returns simply to break even with an equivalent annuity.

This is not a theoretical curiosity. Research published by the Institute and Faculty of Actuaries and others has attempted to quantify this crossover — the age at which staying in drawdown ceases to be actuarially efficient. The consensus in the UK literature typically places this crossover in the late seventies to early eighties, though it varies with interest rates, annuity rates, investment costs, and individual mortality expectations.

The Crossover Problem: When Does Drawdown Stop Winning?

The crossover age — the point at which annuitisation becomes the more efficient choice in expected value terms — is not a single fixed number. It depends on several variables:

Annuity rates. When annuity rates are high (as they were in 2022–2023 following rapid interest rate rises), the income an annuity provides per £100,000 of capital is greater, and annuitisation becomes more attractive at a younger age. When annuity rates are low (as in the 2010–2021 period of near-zero interest rates), drawdown has to be sustained for longer before an annuity would become competitive.

Investment portfolio returns. If a drawdown portfolio consistently earns, say, 5–6% per annum net of charges, the crossover age is pushed later. If returns are lower, or if sequencing risk hits early in retirement, the crossover can arrive earlier.

Health. An individual in poor health may not live to the crossover age. For someone with a significantly reduced life expectancy, annuity purchase is generally unattractive from a financial standpoint (though enhanced annuities available to those with certain health conditions can alter this calculation). Conversely, someone with exceptional longevity expectations — a 68-year-old with excellent health, family history of reaching 90+, and a non-smoking lifestyle — is precisely the type of person who benefits most from longevity-pooling.

Inflation linking. An annuity with RPI (or CPI) escalation costs significantly more than a level annuity but provides inflation protection over a long retirement. The relative attractiveness of a level vs escalating annuity depends on your view of inflation over your expected retirement period.

Partial Annuitisation: The Rational Compromise

Given that mortality drag becomes significant only with advancing age, and that drawdown retains advantages at earlier ages (flexibility, death benefits, investment upside), the rational strategy for many retirees is not all-or-nothing, but a partial annuitisation approach.

Under a partial annuitisation strategy, a portion of the drawdown pot is used to purchase an annuity that covers essential expenditure — utilities, food, housing costs, insurance — while the remainder stays in drawdown for discretionary spending and potential estate building.

The annuity portion eliminates longevity risk on the essential spending floor. The drawdown portion retains flexibility and upside. Together, they create a floor-and-upside structure (as discussed in our guide on sustainable withdrawal rates) that addresses the core risk of each approach.

The proportion to annuitise will depend on:

• The ratio of essential to discretionary expenditure
• State Pension income (which already provides an annuity-like floor)
• Any DB pension income already in payment (similarly)
• Health and expected longevity
• Estate planning objectives
• Current annuity rates

A common planning approach is to model the "floor" — the minimum income required to maintain a basic acceptable standard of living — and then secure that floor through State Pension, any DB income, and if necessary an annuity purchase. The remainder of the pot is left in drawdown.

Actuarial Neutrality and the Escalating Cost of Delay

A concept related to mortality drag is actuarial neutrality — the idea that a pension scheme or annuity provider should, in theory, price a delayed annuity purchase at exactly the same present value as an immediate purchase, adjusting for the time value of money and mortality probabilities. In a perfectly efficient market, there would be no gain from waiting.

In practice, annuity providers do not operate at actuarial neutrality. They earn a spread above gilts to cover their costs and profit. This means that the comparison between annuitising now versus waiting is not simply a question of investment return — the pricing structure of commercial annuities introduces inefficiencies.

What this implies for planning: delaying annuity purchase is not automatically advantageous, even if you believe your investment portfolio can grow in the interim. The annuity rate available in ten years' time is uncertain. If you delay and your health deteriorates, you may lose access to standard annuity terms. Deferring to avoid annuity purchase altogether means running out of time to benefit from longevity pooling precisely when it would be most valuable.

Reviewing Your Strategy at Key Ages

A sensible approach for drawdown investors is to build mortality drag into periodic strategy reviews, with explicit consideration at key ages:

• Age 70–72: Review whether State Pension and any DB income adequately cover essential spending. Begin modelling partial annuitisation for the income gap.
• Age 75: At age 75, the income from uncrystallised funds paid out as a lump sum becomes subject to income tax (the tax treatment of death benefits also changes, shifting from potentially tax-free to being taxable for beneficiaries). Mortality drag is beginning to become material. Assess whether a floor annuity purchase is appropriate.
• Age 80+: Mortality credits are now substantial. If the investment portfolio has performed well, this is a natural point to consider converting a meaningful tranche to a guaranteed income.

These reviews should also cover whether health changes might qualify you for an enhanced (impaired life) annuity, which could offer significantly better terms than a standard rate.

How Global Investments Can Help

Mortality drag is the kind of technical concept that is rarely surfaced by default in drawdown planning — yet it is one of the most important long-term factors in retirement income efficiency. Global Investments provides actuarially informed retirement income planning that integrates drawdown management with annuity strategy, covering:

• Quantifying the mortality drag cost for your specific age, health profile, and portfolio
• Modelling the crossover point under different investment return and longevity scenarios
• Partial annuitisation strategy — identifying the right floor and the right time to annuitise
• Enhanced annuity access for clients with qualifying health conditions
• Drawdown investment strategy designed with the long-term transition to greater certainty in mind

Many clients who received excellent advice at 65 find that their strategy needs a meaningful update by 75 or 80. If your drawdown plan has not been reviewed with mortality drag in mind, we can help.

This guide is for educational purposes only and does not constitute regulated financial advice. Annuity rates and mortality tables change over time. Always consult an FCA-authorised adviser before making irreversible retirement income decisions.