When combining annuities and mutual funds makes sense, or not

If there's one financial concern that millions of Americans share, it's anxiety about running out of money in retirement.

Annuities are designed to address this fear by providing a stable stream of cash flow that you can't outlive. Mutual funds, especially those focused around stock investments, play a potential role by offering a path to greater returns than annuities might provide, with more flexibility. But neither of these options alone has solved the basic worry about outliving one's income and assets.

Could they do a better job if combined?

That's what some financial companies are trying with relatively new funds that incorporate annuities in various ways.

A new report from investment researcher Morningstar examines the trend of combining annuities with "target-date" funds, which hold investments that grow more conservative as your retirement gets closer. For example, a typical growth fund might hold stocks more or less permanently, but a target-date portfolio usually would start out investing entirely in stocks, then over the decades gradually move into bonds.

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What fund-annuity combinations look like

Over the past few years, roughly a dozen fund groups have incorporated annuities with target-date funds in an attempt to provide investors with more income in retirement. These target-date funds "are looking to succeed where others have fallen short by including insurance against running out of money in the form of annuities," the Morningstar researchers wrote.

But the new products are complex, and they charge expenses on top of those for the underlying target funds — and these costs aren't always transparent.

The costs tend to run lower for funds that use straightforward income annuities compared to more complex variable annuities, the latter of which might add 0.5% to 1% in additional yearly fees, Morningstar noted. Variable annuities can hold a range of investments, including stocks, and include other features.

With the more-straightforward income variety of annuity, investors can lock in an income stream based on how much they invest, current interest rates and other factors. For example, a $200,000 lump sum placed recently into an income annuity would qualify for a payment of about $1,200 a month for life, Morningstar said.

For people already considering annuities, the new target-date funds might be attractive, as they choose the annuity so that investors don't need to "sort through myriad complicated options," the report said.

But that's where the simplicity ends. Morningstar views the complexity of these combined products, along with often-hefty fees, as drawbacks.