None of us should be leaving our retirement to chance. Without having a solid retirement plan in place, you may end up with insufficient funds and many stressful years. If you're married, you have even more ducks to get in a row, because you need to have certain conversations with your spouse before you retire. (Ideally, these conversations should take place long before retirement and might be revisited now and then.)

Here are five important questions for pre-retirees to discuss together, to arrive at a common understanding. Having these talks -- and acting on them -- can minimize unpleasant surprises in your later years.

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1. What's our financial retirement plan?

Drafting a solid retirement plan involves figuring out how much income you'll likely need in retirement and how you'll get it. (Ideally, be a little conservative and aim for more than you think you'll need.)

A key way to get what you need is to save aggressively and invest effectively. The table below shows some of what's possible over time.

Source: Calculations by author.

What's effective investing? Well, for long-term money, it's hard to beat the stock market, and for investing in the stock market, it's hard to beat index funds. You might consider a simple, low-fee index fund such as the Vanguard S&P 500 ETF (VOO 0.54%). There are other powerful index funds to consider, as well.

For many people, it's smart to aim to have multiple income streams in retirement, which might include dividend-paying stocks, rent checks from tenants in properties you own, interest-bearing investments, annuity payments, interest from bonds, and so on.

2. When will we claim Social Security?

There's more to Social Security than many people realize. For starters, when to start collecting Social Security is an important decision to make, and one you should coordinate with your spouse.

You can start collecting as early as age 62, or you can delay, up to age 70. Starting early means smaller benefit checks -- though you'll collect many more of them than someone who waits until, say, 70. For a majority of retirees, the best strategy is to wait until age 70. There are multiple ways to increase your Social Security benefits, too.

One sensible strategy for married folks is for the higher earner to delay until age 70, in order to maximize their benefit. The lower earner might start collecting early, late, or somewhere in between, as needed. The rationale is that when one spouse dies, the survivor will be able to collect whichever benefit is larger for the rest of their life.

3. How will we handle healthcare costs?

Healthcare costs in retirement are no joke, so it's smart to plan for them and to seek ways to keep them in check as much as possible. According to Fidelity, a 65-year-old person who retired in 2024 could expect to spend $165,000, on average, on medical and healthcare expenses throughout their retirement -- not including long-term care, over-the-counter medications, and most dental services. A married couple might assume an average cost of $330,000.

You may spend less, especially if you're healthy, but even healthy people get surprising and unwelcome diagnoses sometimes. (Still, a good strategy is to get healthy and stay that way, if possible, in order to try to minimize the costs.)

A key decision to make will be about Medicare and whether you opt for "original Medicare" or popular Medicare Advantage plans. Be sure to read up on them carefully, because each option has its pros and cons, and switching between them may not be as simple as you think.

4. What's our non-financial retirement plan?

Retirement isn't just about money, of course. It's worth spending some time now and then discussing how you envision your future years. For example, one of you might want to travel, travel, travel, while the other might want to golf, garden, and volunteer. Aim to get on the same page and compromise where needed.

Many retirees find themselves surprised by some downsides of retirement. They may feel at sea without a schedule to stick to and may feel purposeless without work to do. Plan to keep busy. Start some hobbies or dive into existing ones. Develop an active social network, too.

5. What estate planning actions should we take?

Finally, you should both tend to your estate planning. Fail to do so, and your heirs may end up paying more in taxes than necessary, and there may be extra hassles and even heartbreaks.

Here are some key things to do:

• Consider hiring an estate planning professional, such as an estate planning attorney.
• Have your wills drawn up and beneficiaries and wishes noted.
• Have durable power of attorney forms prepared. These let a designated person make legal and financial decisions for you if and when you can't.
• Have healthcare power of attorney forms prepared, designating someone to make medical decisions for you, if and when that's necessary.
• Have a living will, spelling out your preferences, such as whether you'd like to be kept on life support and in which situations.
• Look into whether setting up a trust would make sense for you.

So if you're married, start talking about these topics now, and take necessary actions sooner rather than later. Even if you're still in your 40s, it can be smart to have plans in place. It might even help you sleep better.