Can you earn 8 percent on a fixed annuity, guaranteed? Online ads often make this promise.

Those ads are misleading. They’re not completely false, but they set unrealistic expectations. We have to talk clients back down to reality.

The truth is complex. Some annuities do indeed offer an 8 percent rate guarantee. But there’s a catch. That doesn’t guarantee the annuity’s actual return. Instead, it guarantees the growth of an income account value created by an optional rider.

It’s not money you can withdraw. It sounds too good to be true, and it is.

Buying a lifetime income rider creates the income account value, which grows at a guaranteed annual rate of 4 percent to 8 percent. The income account value is used to calculate the amount of future guaranteed lifetime income payments. Most insurers charge an annual fee of about 1 percent of the annuity value for this option, typically available with indexed annuities.

That’s why some annuity marketers get away with claiming a misleading 8 percent return. Those ads are usually placed by marketing firms that sell the leads to annuity agents.

What can you really earn?

The top rate for a five-year fixed-rate annuity is 4.01 percent, according to AnnuityAdvantage’s online rate database. For a 10-year annuity, it’s 4.31 percent, and for a three-year guarantee, it’s 3.10 percent.

These are good rates that build savings safely. You don’t need to exaggerate.

Like bank CDs, multi-year annuities offer a guaranteed rate for a set period of time. But they usually pay substantially more interest than bank CDs of the same duration. Another key advantage: interest is tax-deferred as long as it’s left to compound in the annuity.

An income rider is a good deal for some people

It’s unfortunate that some marketers muddy the waters with hype. The income rider can be a worthwhile purchase for some people.

Unlike the multi-year deferred annuities mentioned above, fixed indexed annuities provide an interest rate that varies from year-to-year. They offer a chance to get a good portion of the stock market’s gains while offering complete protection from loss. Principal is guaranteed.

A saver can add another layer of protection with a lifetime income guarantee rider. But it makes sense only if it meets your needs and your strategy. You should feel sure that you’ll use the feature eventually.

But if you do use it eventually, the income rider can be a wise purchase. It can produce more guaranteed lifetime income at a future date while giving you complete control over your money. Since you don’t set the date for income payments to start when you buy the annuity, you retain planning flexibility.

Normally, when you convert an annuity into an income stream through annuitization, its cash surrender value becomes zero. That’s not the case here. You still own the full value of your annuity.

You can choose any time to start receiving lifetime income. The amount is determined by the income account value along with your gender and age at the time you start receiving payments. Prior to activating lifetime income, the income account value typically grows at a guaranteed annual compounded rate of 4 to 8 percent.

After income activation, annual payments are deducted from the contract value. If that value ever reaches zero, annual income payments are still guaranteed for the remainder of your lifetime, but the annuity would no longer have any cash surrender value.

Lifetime income riders vary dramatically from one annuity company to the next. Shop around and compare.

An income rider is just one way among several to guarantee your future income. Other ways include buying a deferred income annuity or annuitizing a fixed annuity when you retire.

Annuities come in many types and variants that meet a wide variety of needs. It’s smart to shop around. Don’t be put off by misleading advertisements that can cast a negative light on a unique set of retirement-planning tools.

Annuity expert Ken Nuss is the founder and CEO of AnnuityAdvantage, a leading online provider of fixed-rate, fixed-indexed and immediate-income annuities. He launched the AnnuityAdvantage website in 1999 to help people looking for their best options in principal-protected annuities.