A growing number of Americans are heading into their retirement years as single adults. With no spouse to rely on, these individuals need to take extra precautions to ensure a secure retirement.

Due in part to increases in divorce rates and the proportion of the population that never married, about 35% of 50- to 54-year-olds were single in 2010, up from almost 29% in 2000, according to the Census Bureau. Among 55- to 64-year-olds, 33% were single in 2010, versus 30% in 2000.

Because the cost of living for single retirees is about 40% to 50% higher than for empty-nest couples, financial advisers recommend that they save at least 15% of their pay for retirement. "Most couples have two incomes and shared economies of expenses," says Brian Pon, an adviser with offices in Berkeley and Corte Madera, Calif. In contrast, "for single savers, the responsibility of saving falls squarely on themselves."

Advisers say it's especially important for single individuals to take steps to safeguard their nest eggs from creditors and the prospects of unemployment or disability.

To prepare for a potential job loss, Natalie Briaud Pine, a financial adviser in College Station, Texas, recommends paying off debt and setting aside enough cash to finance living expenses for the amount of time it is likely to take someone in your industry to land a new job.

While those without dependents may have little need for life insurance, advisers say it's important to carry adequate levels of liability, disability and long-term-care insurance.

In the event of an illness or injury, disability insurance replaces a set percentage of your income -- typically, 50% or 60% -- often up to a maximum period of time. Some employers subsidize coverage or provide it free. But Loretta Nolan, a financial adviser in Old Greenwich, Conn., says the benefits often fall short of what single employees would need. That's because, in addition to replacing only about 60% of the employee's salary, disability benefits are subject to income tax when an employer pays the premiums.

To make up for at least some of the shortfall, Ms. Nolan often suggests that single clients purchase supplementary coverage. (When an individual foots the bill, the benefits are tax-free.)

Another reason to purchase a policy on your own: If you leave your job, you can take the coverage with you.

For clients who lack a designated caregiver, Ms. Nolan often recommends long-term-care insurance.

Moreover, she says it's crucial that those without a spouse speak to an attorney about giving someone the legal right to manage their affairs and make medical decisions on their behalf if they can no longer do so.

Ms. Nolan also says singles with pets should consider appointing a caregiver and making a bequest to cover future veterinary bills.

—Email: next@wsj.com