Saving enough for a secure retirement is a tough proposition for anyone, regardless of age or income. But if you happen to be born with a pair of X chromosomes, it's that much harder still.
Indeed, women face a unique set of challenges when it comes to meeting their financial goals, including longer life expectancy, fewer years in the workforce and persistently smaller paychecks than men. Marital status and occupation aside, they are simply at greater risk of outliving their assets.
The poverty rate for women age 65 and older is 16 percent, compared with 9 percent for men of the same age group, according to the U.S. Census Bureau.
"Women have a bigger challenge because they need more money than men, but the data all show that they actually have less," said Cindy Hounsell, president of the Women's Institute for a Secure Retirement.
The growing prevalence of single women and divorcees, she said, puts added strain on disposable income and the ability to save.
Some 37 percent of American women 65 and older live alone, compared with 19 percent of men the same age. And almost half (47 percent) of women 75 and older live alone, the Council on Contemporary Families reports.
That's not to say women are financially doomed to fail, Hounsell said. They just need to adjust their long-term savings plan and embrace opportunities to bridge the gap.
That begins with a safety net for future medical expenses.
Because they tend to live longer than men - an average of nearly five years longer, according to the Institute for Health Metrics and Evaluation - women need to budget for higher health-care costs in their twilight years. These include co-pays, deductibles, medication and, most important, assisted-living services, which are not covered by most insurance plans.
Health-care costs are among the biggest expenses for retirees.
A 65-year-old couple retiring today with traditional Medicare insurance coverage will need a projected $220,000 to cover out-of-pocket medical expenses throughout retirement, not including any costs associated with nursing-home care.
AARP reports that more than 70 percent of nursing-home residents are women, whose average age of admission is 80 years old.
The median annual rate for a private nursing-home room in 2013? Nearly $84,000, according to financial services firm Genworth. That can deplete a lifetime's worth of savings in just a few years.
While long-term care insurance, which covers assisted-living, nursing-home and at-home care, can be a valuable tool for everyone, Neil Brown, a certified financial planner with Burkett Financial Services, said retired women can potentially benefit from such coverage the most.
"Long-term care insurance is important, and especially so for a widow, divorcee or childless female, since there may be fewer people around to care for them," he said.
Statistically, women are the primary caregivers in the home and are thus far more likely to put their careers on hold when their kids are young and to retire early to care for aging parents.
The Women's Institute for a Secure Retirement reports that women typically work 12 fewer years than men over their lifetime, which means they contribute less to Social Security, resulting in a smaller benefit.
When they do return to work, women are also more likely to accept part-time jobs that provide for better work-life balance but rarely offer employer-sponsored retirement plans or matching-contribution benefits. That means fewer opportunities to fund their nest eggs.
Read More Retirement's not for everyone
While the income gap is steadily shrinking, women also continue to earn less than their male counterparts when they are employed. Census Bureau data show the median earnings of men who worked full time in 2012 was $49,398 vs. $37,791 for women.
Thus, they have less to contribute to a tax-deferred retirement plan.
Those denied access to an employer-sponsored plan should separately fund an individual retirement account, or IRA (traditional or Roth). How much a woman invests depends on her goals for retirement and her financial picture - but 10 percent of income per year is a good starting point, Brown said.
Women (and men) can also compensate for undersaving by working longer and postponing their Social Security benefits to permanently increase their future benefit, said certified financial planner Brett Horowitz, a principal and vice president at Evensky & Katz.
If your full retirement age is 66, for example, you would get 132 percent of your monthly benefit - for life - by waiting to collect until age 70.
"When it comes to Social Security, married couples sometimes assume that the husband should do what's best for him and the wife should do what's best for her, but really the goal is to try and maximize total earnings for both," Horowitz said. "Unless the husband is really ill and can't afford to wait, he should delay benefits to help himself and his wife later on."
Read More Advisors rein in risk-hungry clients
Women can further mitigate longevity risk by ensuring their income streams are sufficient to cover living expenses.
That includes Social Security, pensions and portfolio withdrawals, which should start at roughly 4 percent for most investors and adjust higher annually for inflation, Brown said.
If your expenses are greater than your income and you've not yet quit your job, you should postpone your retirement, spend less and sock more money away.
If you're already retired, your choices are harder. You'll need to either lower your standard of living, downsize to reduce fixed expenses or take in a roommate to ensure that your savings last.
"The one thing we all control is our spending," Brown said. "We all need to realize that what we do today could lead to reduced spending and downsizing later in life."
Be sure, too, that you don't get too conservative too soon with your asset allocation. Unless you are independently wealthy, said Brown, stocks should still comprise 50 percent or more of your portfolio to offset the effects of inflation and generate the income you need.
Read More A peek inside the 401(k) test lab
Annuities - insurance products that pay out lifetime income in exchange for a lump-sum payment or series of payments - have long been used to create guaranteed retirement income, but with interest rates so low, it's worth considering alternatives, Brown said.
"If you can find a low-cost, no-commission fixed annuity with no escape fee, then annuitizing maybe 15 percent of a portfolio can be beneficial," he said, noting dollar-cost averaging over the next 24 months - or buying smaller increments over a longer period of time - might work best, given the interest-rate environment.
To generate stable income, some financial advisors recommend retirees own mostly dividend-paying stocks and laddered bonds, in which the bonds' maturity dates are evenly spaced to minimize interest-rate risk and increase liquidity.
Read More Are bonds still a safe bet?
But Horowitz at Evensky & Katz favors a different approach.
"It doesn't make sense to rely on dividend stocks and bonds, because your income rises and falls depending on their performance," he said. "It also forces you to buy only dividend stocks and certain bonds to meet your income threshold. You may be forced to buy higher-yielding junk bonds or stocks you wouldn't otherwise wish to own."
For his retired clients, Horowitz maintains a diversified equity and fixed-income portfolio with an income goal in mind. He then parks 12 months' worth of living expenses into a liquid interest-bearing account that his clients can use as they would a checking account.
The money is replenished with earnings from their investment portfolio, which allows six months or more of flexibility to delay those withdrawals when the market is down.
"That way, the client knows where their groceries are going to come from for the next year, they can sleep at night, and they can stay invested in equities," Horowitz said.
Women face significant challenges when it comes to planning for a comfortable retirement. Understanding the obstacles and opportunities, however, can make all the difference in the size of their future nest eggs.
"Women sometimes leave their finances to the back burner," said Vielka Burey-Jacas, a certified financial planner with Women's Financial Advisory Group, noting younger generations are admittedly more "hands on."
"They take on many different roles in their lives, but they forget to think about themselves and their own future," she said. "I encourage women to educate themselves on this topic and join groups of women that offer workshops."
More From CNBC
- Reverse mortgages: Easy money or dumb move?
- Obama's budget plans bad for some 401(k) savers
- Plan for financial independence, not retirement
- Retirement Benefits
- Personal Finance - Career & Education
- certified financial planner