Your expenses don’t end with your paychecks, but creating a reliable income stream in retirement can be tricky. The right choices can result in sustainable income for the rest of your life. The wrong choices could leave you uncomfortably short of cash.

In fact, retirement includes so many important, potentially irreversible decisions that most people could benefit from a few sessions with a fee-only, fiduciary financial planner. (Fiduciary means the adviser is committed to putting your interests ahead of their own.)

These ideally would start about 10 years before retirement. Understanding some key concepts could make those discussions easier – or keep you from making serious mistakes if you take a do-it-yourself approach.

Maximize Social Security

Social Security will make up 60% to 80% of most retirees’ income, so maximizing those checks is essential, says actuary Steve Vernon, a consulting research scholar at the Stanford Center on Longevity.

Social Security checks can start at age 62, but abundant research shows most people are better off delaying. Waiting until 70, when benefits max out, is typically the optimal strategy for single people and the higher wage earner in a couple, says Vernon, author of “Retirement Game-Changers.”

Situations can vary, though, it’s smart to consult Social Security calculators to help decide when to start. AARP’s site has a free one, or search for more sophisticated versions from Maximize My Social Security ($40 and up) and Social Security Solutions ($20 and up).

A planner might recommend tapping retirement accounts or working just enough to substitute for the income you would otherwise receive from Social Security.

Other guaranteed income

Ideally, fixed expenses in retirement would be covered by guaranteed income, such as Social Security and pensions, so that your basic lifestyle isn’t jeopardized by stock market fluctuations. If those sources aren’t enough to cover basic costs, an income annuity could help fill the gap, says certified financial analyst Wade Pfau, author of “Safety-First Retirement Planning.”

Income annuities are insurance products that can offer a lifetime stream of monthly payments in exchange for a lump sum. Unlike variable annuities or other investments, the amount you get doesn’t vary if the stock market goes up or down.

Another option could be a reverse mortgage, a loan that can convert some of your home equity into a stream of monthly checks. If you have a lot of equity but still have a mortgage, a reverse mortgage could pay off your loan and eliminate those monthly payments.

Sustainable withdrawal rate

Financial planners’ 4% rule suggests withdrawing 4% of your portfolio the first year, adjusting the amount each year afterward for inflation. This strategy historically has posed a low risk of running out of money.

Some planners, however, worry that 4% may be too high given current low interest rates and high stock valuations. The “Spend Safely in Retirement” method, which Vernon created with the help of the Society of Actuaries, recommends using annual withdrawal rates based on the IRS’ required minimum distribution rules.

The percentage rises slightly each year according to age. A 60-year-old might withdraw 2.72%, a 65-year-old would tap 3.13% and a 70-year-old would take 3.65%. The withdrawal would be made at the end of each year, then the money is moved into a savings account or other investment that protects the principal, so it’s available to spend the following year without risk of market losses.

Unlike the 4% rule, the “Spend Safely in Retirement” approach poses no risk of running out of money but can result in income that varies considerably from year to year. Retirees who have their basic expenses covered by guaranteed income might look at their portfolio income as a bonus, Vernon says. A bigger one can pay for splurges, while a smaller bonus might require cutting discretionary spending.

Stay invested

Many retirees are tempted to move their money into “safe” investments such as bonds, certificates of deposit or savings accounts. Unfortunately, those investments might not keep up with inflation over time. Devoting at least 50% of investment portfolios to stocks – ideally using a low-cost target date, balanced or stock index fund – can produce more income over time, Vernon says.

Your work isn’t done once you create a retirement paycheck. You’ll still need emergency funds for unexpected expenses and a strategy to pay for long-term care, among other tasks. But establishing a reliable income stream can help you meet your regular expenses in retirement without worrying you’ll run out of cash.

Liz Weston is a columnist at NerdWallet, a certified financial planner and author of “Your Credit Score.” Email: [email protected]. Twitter: @lizweston.