• Current and prospective retirees want the most income possible.
• For some, that may prompt the question as to whether or not paying off a mortgage makes sense.
• The answers to that and other big money questions are not one-size-fits-all, a new retirement book finds.

When it comes to retirement, we all want to have the most income possible.

But exactly how to achieve that goal is confounding question for most people.

In her new book, "How to Retire: 20 Lessons for a Happy, Successful and Wealthy Retirement," Christine Benz, director of personal finance and retirement planning at Morningstar, seeks to get expert answers to the most vexing retirement questions.

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In a series of Q&As with retirement thought leaders, Benz digs into topics including how retirees can identify a safe withdrawal rate from their portfolios to ensure their assets last, when to claim Social Security to get the biggest benefits and when it makes sense to buy an annuity to increase guaranteed monthly income.

There's no one-size-fits-all answer. Even experts don't agree on the best approach.

Older Americans have significant equity

As current and prospective retirees consider how to handle their assets, their homes are one area where they may have a lot of equity tied up, prompting the question, "Should I pay off my mortgage?"

Homeowners ages 65 and over had a median home equity of $250,000 as of 2022, up 47% from 2019, according to the Joint Center for Housing Studies of Harvard University.

As some retirees relocate, they are turning to that equity in lieu of taking on a new mortgage.

"We are seeing more all-cash buyers," said Jessica Lautz, deputy chief economist at the National Association of Realtors.

In its 2023 annual report on home buyers and sellers, the trade association found about a third of younger baby boomers ages 59 to 68 who had recently purchased homes with all cash. For older baby boomers ages 69 to 77, that goes up to 43%, and for the silent generation, that rises to about half.

Legacy homeowners may also benefit from knocking down their mortgage debt balances, which can free up more monthly income, some experts argue.

"If you can reduce your ongoing spending, that can provide a lot of peace of mind and give you a lot more wiggle room to be flexible with your portfolio withdrawals," Benz said.

Mortgage rates may affect payoff calculus

The mortgage payoff calculus may change based on whether people can outearn their mortgage rates with safe, guaranteed investments, Benz said.

Benz and her husband paid off their mortgage more than a decade ago. But what was the right answer then might not be today, she said.

Whether or not to pay off your own mortgage — if you're retired or not — comes down to both whether it makes sense financially and how it feels emotionally, JL Collins, a financial blogger and bestselling author, tells Benz in her book.

For mortgages that are 3% or less, it doesn't make sense to pay off, since better returns are available in the stock market, Collins said. For mortgage rates that are 6% or more, paying that balance off will provide a guaranteed return. And for rates between 3% and 6%, it depends on what makes borrowers most comfortable, he said.

Benz said she recently saw the other side of the debate when she suggested a friend use their inheritance to pay off her mortgage. Her friend was completely averse to the idea, she said.

"It's like, 'Well, why not get rid of this regular monthly bill?'" Benz said. "And her point was, 'No, seeing my portfolio shrink by that much would feel terrible."

Ted Jenkin, a certified financial planner and the CEO and founder of oXYGen Financial, a financial advisory and wealth management firm based in Atlanta, tells CNBC that he typically recommends clients pay off their mortgages when it makes sense, even if they are not retired.

"There are a lot of people that I help pay off mortgages that say, 'It's so great to drive home and to know that I own that property; nobody can take it away from me,'" said Jenkin, who is also a member of the CNBC FA Council.

Getting rid of mortgage debt can also provide career flexibility to start a business or pursue other goals, he said.

Admittedly, the argument over whether to pay off mortgages is "much more emotional and psychological than it is financial," Jenkin said.

In other words, there is no one right answer. The same goes for other topics Benz touches on in her book.

Emotional questions to prepare for retirement

Notably, the book's content is split about evenly between financial and non-financial content. The big money questions people ask themselves to prepare for retirement are just as important as the emotional ones.

What brought you joy while you were working may change in retirement, Michael Finke, a professor of wealth management at The American College of Financial Services, tells Benz. As such, you shouldn't just think of retirement as relaxation, because you need something to relax from.

While goals such as playing golf or visiting your children may take up a few days, ask yourself what the whole 365 days of a year in retirement will look like, Jamie Hopkins, chief wealth officer at WSFS Bank, tells Benz.

Ultimately, retirement offers individuals a new chance at reinvention.

It's a chance to ask yourself, "What would I regret?" Often, it's the chances we don't take that end up haunting us on our death beds, Jordan Grumet, a hospice doctor, author and podcast host, tells Benz.