Bill Benson and his wife had planned to fortify their retirement savings once their children left home, so they’d have enough to travel and relax. But at 68, Benson is still working full-time, and that empty nest he envisioned isn’t so empty. Benson’s eldest daughter moved home with her two young sons after a divorce, and the two children he and his wife adopted later in life are just now finishing high school and starting college.

Along the way, Benson exhausted a federal pension to pay for one son’s special needs, and he expects to keep supporting that son, as well as his grandsons, now ages 3 and 5, through retirement—whenever that may come. “It’s nose to the grindstone,” says Benson, who consults full-time on aging policy. “We had to make choices to spend on our kids—because you have to do that. I guess it’s a crazy modern family, but we also know we are fortunate, with decent jobs and good incomes.”

Benson’s situation illustrates one of the biggest threats to your retirement—your kids. And it’s not just about the high cost of college. Parents have long tried to set up their children for success, but today that assistance is costing ever more, and lasting far longer. The cost of a four-year private college averages $48,500 a year, double what it did in the late 1980s. And financial independence is increasingly delayed. About 15% of 25- to 35-year-olds were living at home in 2016, based on a Pew Research report. That’s five percentage points higher than the share of Generation Xers living at home when they were the same age, and almost double the share of today’s older retirees who were in the same situation years ago.

Parental help often starts small, covering expenses such as cellphone bills, car payments, groceries, or health insurance. But temporary assistance can quickly turn permanent and pricey, financing rent and down payments, grandchildren’s college educations, and support for offspring going through divorce or battling drug addiction.

Nearly 80% of parents give some financial support to their adult children—to the tune of $500 billion a year, according to estimates by consulting firm Age Wave. That’s twice what parents put into retirement accounts, according to a 2018 survey from Bank of America Merrill Lynch and Age Wave. Almost three-quarters of respondents acknowledged putting their children’s interests ahead of their own retirement needs.

Ten years of a bull market and a growing comfort with debt have made this largess easier to rationalize. But incurring additional costs just before or just into retirement can be problematic—especially now, as the outlook for stock returns is about half what it was in the past 10 years. While most people are well aware of the threat posed by a sharp market downturn just as they begin to tap their savings, they’re less attuned to how helping their children can pose a similar danger and imperil decades of judicious savings.

“House prices and retirement portfolios have gone up measurably, so we have a generation of retirees feeling very flush,” says Lynn Ballou, a Certified Financial Planner based in the San Francisco Bay area for EP Wealth Advisors. “But they are also going to probably live much longer than their parents, and probably need long-term care, so those extra resources they think they have may be a mirage.”

Of course, some people have enough of a cushion to offer their adult children help. But even then, financial advisors are increasingly wary of encouraging assistance: Well-meaning parents can sometimes create more harm than good—not just to their own retirement, but also to their children’s financial and physical well-being.

So how can parents help without hurting their retirement or their kids’ futures? We surveyed financial planners for the biggest challenges and how best to strike the right balance.

Paying for college

It’s an old saw in the financial-planning industry that you can borrow to pay for college but not to fund your retirement. That may be true, but with $1.5 trillion in education debt weighing on parents and students, borrowing for higher education is an increasingly dubious proposition. So much so that the Trump administration wants Congress to limit federal student loans to help curb rising college costs.

Nearly 70% of parents surveyed by T. Rowe Price said they would be willing to delay retirement to pay for college. That’s a sentiment prevalent among the Asian and South Asian families that Sahil Vakil works with at his financial-planning firm MYRA Wealth in Jersey City, N.J. “There is almost a cultural requirement that parents pay for education, which creates a societal pressure,” says Vakil. “They are not thinking about their retirement, and put their children ahead of their needs.”

And it shows in the data. Education debt held by U.S. households went up more than sixfold from 2001 to 2016, with families headed by someone age 40 or older representing the biggest jump, according to a December report from the Federal Reserve. Even more troubling: More retirees are violating the golden rule of paying off debt by the time they collect their last paycheck. Of those ages 65 to 74, 70% have debt; 39% of it housing-related—double the amount for that age group in 1992, according to the Employee Benefit Research Institute.

The low interest rates that most people have on mortgages and car loans make entering retirement with debt more palatable, but that doesn’t mean parents should raid their savings—or divert money from retirement funds to college accounts. When it comes to saving for college, the advice goes like this: Secure an emergency fund, max out the retirement accounts, and then contribute to a 529 college-savings plan. These grow tax-free, and withdrawals are tax-free, too, as long as the money is used for education expenses.

Think you may be eligible for financial aid? All the more reason to focus on retirement savings: 401(k) plans, IRAs, and other retirement accounts are excluded from the calculation; 5.64% of 529 balances are included. Each parent can contribute $15,000 a year to a 529 before it begins to impinge on the $11.2 million lifetime gift-tax limit. The 529s can also be superfunded for five years of contributions, which means that grandparents or parents can sock away as much as $150,000 early in the child’s life to kick-start the compounding.

Student Debt Becomes Senior Debt

The amount of student debt held by people age 60 and over has increased dramatically since 2012. In six states the amount has more than doubled.

      25-50%              50-75                75-100            100-125           125-150

Source: CFPB Note: Dollar amounts are nominal and not adjusted for inflation. Latest student debt data as of the end of 2017.

Some states offer a tax credit for investing in their 529 plan—$2,500 in Maryland, $5,000 in New York, and $10,000 in Illinois, for example, while others, such as Pennsylvania and Kansas, offer a deduction, regardless of which state’s plan is used. Each state has its own menu of options, and sometimes it’s better to divvy up a contribution. For example, a couple in New York who plan to contribute $30,000 can allocate $10,000 to the state plan run by Vanguard to get the deduction, and put the other $20,000 in the Utah plan, which Vakil prefers because it offers a broader array of investments and includes funds from Dimensional Fund Advisors.

Getting a realistic idea of what college will cost will better inform the savings strategy—state universities in Pennsylvania and Vermont, for example, charge 40% and 60% more, respectively, than the average in-state tuition, which is $10,230, according to the College Board.

While more-affluent families might not qualify for financial aid, many colleges offer merit aid. Fantastic grades or sports talent helps, but so can geographic diversity—a reason that students on the East Coast may want to apply to schools in the Midwest, says Claire Toth, a financial planner at Point View Wealth Management in Summit, N.J. Toth also recommends finding schools with generous alumni. One way to spot them: Look for universities sprucing up not just dorms and sporting facilities, but also libraries and academic buildings beyond the hard sciences. Getting aid packages from two schools on the fallback list can help a student negotiate a package from their first choice.

As for the rest of the bill? Retirement accounts should be a last resort, and possibly not even that. IRAs can be tapped for qualified educational expenses before hitting age 59½ without incurring a 10% tax penalty, as you otherwise would. But the withdrawal would be taxed as ordinary income, at rates almost certainly higher than what you’d pay in retirement. What’s more, you’ll lose the huge benefit of tax-free compounding of your retirement savings.

A smarter strategy

A better option would be to tap a taxable account, since capital-gains taxes are lower. For parents with resources but not liquidity, Angie O’Leary, head of wealth planning for RBC Wealth Management in the U.S., says some clients can leverage their stock portfolios through a securities-based line of credit, or nonpurpose loans. Unlike the margin loans used to buy stock, these are tied to the London interbank offered rate, a global interest-rate benchmark, and are less costly than federal parent PLUS loans.

“When you sell a stock, it’s permanent. But if you need cash flow to meet a tuition payment and can pay it back, this allows you to have the money to do so without liquidating in a downturn—or selling a stock with good momentum,” O’Leary notes.

When it comes to utilizing the equity in your home, financial advisors are split. Some worry about taking on additional debt near retirement, but some view home-equity lines of credit, or Helocs, as viable options, assuming interest rates are still low and more attractive than the federal parent loans. But the interest on a Heloc is no longer tax-deductible if the money is used for college, or anything not directly related to home improvement.

There’s also the tough-love approach. Advisors tell clients to look at college like any other investment—through the lens of risk and return. If students will take on debt, advisors recommend limiting the borrowing to an amount they can pay off in five to 10 years, based on expected earnings.

Post-college support

It’s the stage after college that becomes even more problematic for many of Davon Barrett’s clients at Francis Financial. Parents usually plan for college expenses, but most don’t expect to assist their children for years beyond. Plus, living expenses in a small college town can seem like pocket change, compared with paying rent and helping to fund a lifestyle in New York or San Francisco. “Parents worked this hard to get their kid to adulthood by sticking with their financial plan to pay for college,” says Barrett. “Helping their children now can put them in financial jeopardy.”

It can also upend their lives. Mercedes Bristol was engaged to marry a retired judge and beginning to plan for a comfortable retirement with pensions from two jobs. Their plan was to travel and buy a new home. Instead, at age 57, Bristol ended up adopting her son’s five children, forcing her to retire early to care for them. She forfeited full medical coverage through retirement. She also forfeited her romantic relationship. “I had to give up a lot, like my independence. Now, I’m a single grandmother,” says Bristol, 64. “You try to be there to help your kids. As far as myself, I don’t know about my future retirement plans.”

Bristol, whose youngest grandchild just turned 8, has started a support group for other grandparents in her situation. Their biggest worry is their health, and paying for medical care. There are some three million grandparents taking care of younger children, often as fallout from the opioid addiction crisis.

Temporary assistance with rent or a couple of extra courses can morph into a pattern that lasts for years. When a client said she needed $20,000 annually to help her adult son with various career ventures, Dana Anspach, a certified financial planner and head of Sensible Money in Scottsdale, Ariz., warned that it couldn’t be a regular expense or she would run out of money. “Year nine came around, and we had to tell her the portfolio would last only another seven years. She had a ‘God will provide for me’ mentality, and I told her ‘God has sent you me,’ ” Anspach says. But the client continued to give her adult son money, leaving her with little more than a small pension and Social Security.

Financial support isn’t just bad for retirees; it can hurt their children as well. Paying for vacations, Uber rides, car loans, and rent can prevent adult children from becoming financially independent, ultimately compromising their financial well-being. Some parents, wanting to be near their grandchildren, swoop in with a down payment for a home in their affluent neighborhood. “What they don’t realize is that they are creating an economic lifestyle their children may not be able to maintain,” Ballou says. Those children then may stretch to fund the extracurricular activities that are part of the community’s lifestyle, or rely on their parents for more assistance.

When an adult child is battling addiction, mental illness, or a medical condition, tough love is harder for financial advisors to recommend. But sometimes footing the bill can create more damage, cutting off the adult child from community- or state-based services and—in instances of addiction—adding to the problem.

So, now what?

For those intent on helping their adult offspring, financial advisors stress running the numbers and bringing the children into the conversation, so they can see what their parents can afford, reducing the guilt some parents feel for saying no. “When money and emotions mix, parents don’t make decisions in their best interest,” says Edythe De Marco, a financial advisor for Merrill Lynch. “Oftentimes, parents get into financial hot water because talking about money has never been that common.”

In sum, giving to children requires good communication and firm boundaries. But striking the right balance can help parents find the feeling that’s so elusive: peace of mind, for their children and themselves.