It’s a common problem: Clients plan to retire in their late 60s. They make a plan with their advisors. Everything’s good.

Then the clients change their minds. They suddenly want to retire sooner. The advisor has no Plan B.

That unexpected change can “have a significant negative impact” says Morningstar in a new study, “The Impact on Retirement Age Uncertainty on Retirement Outcomes.” Advisors who haven’t planned for that eventuality could find their clients running out of money.

An unexpected early retirement can drain the final retirement balances, so much so that the assumptions of the original plan are ruined. And clients often retire sooner than planned.

“The average person who says he is going to retire at age 67, [actually] retires at age 64,” says David Blanchett, head of retirement research at Morningstar and a speaker at Financial Advisor's Inside Retirement conference in Las Vegas on September 26. “You need to prepare your plan with this possibility in mind.”

Add to this the problem that millions of Americans aren’t putting enough aside in the first place to protect a standard of living in retirement. In a recent survey by the Employee Benefit Research Institute, only 17 percent of American workers felt very confident in their ability to retire comfortably. Academics question the precision of the savings gap, but there’s no debate there is one.

“No matter how you slice it … nearly half of Americans have saved nothing for retirement, and the median 401(k) balance is under $100,000 among working age households who have saved something,” says Stephen Wendel, head of behavioral science at Morningstar.

Wendel ran computer simulations on various household retirement plans, estimating which ones would succeed and fail. In his own paper, “Easing the Retirement Crisis: How Financial Planning and Personalized Advice Can Head Off Extreme Austerity,” he looked at eight possible advisor actions and how they would affect these plans.

In these scenarios, retired clients can become “highly dependent” on Social Security, the Morningstar research suggests.

“Many Americans face a scary prospect: needing to survive on much less money during retirement than they’re used to, or not being able to afford a retirement at all,” Wendel writes.

These problems also confront millennials, who, research suggests, aren’t saving enough, who don’t have pensions like previous generations did, and who will likely be facing a future of reduced Social Security payouts.

Great (And Lesser) Expectations

Given the changing circumstances of retirement savings, each plan written by an advisor should have an early retirement option, experts say. It is up to the advisor to anticipate horror stories and figure out a way to survive them.

There are many ways a retirement plan can blow up, Blanchett notes—say, if the client runs into an unexpected health crisis or loses his or her job. Without a Plan B, you’ve wrecked years of work.

Take, for example, a 55-year-old who plans on retiring at age 65 and plans to take out an initial withdrawal rate of 4 percent.

If the retiree suddenly decides to quit at age 55, Morningstar says, now he or she will need 25 percent more savings “to achieve the same income level with the same degree of success, assuming no retirement age variability.”

If a person planned to retire at age 70 but then quits at age 55, that retiree might need 50 percent or 100 percent more in savings, Blanchett says.

It is difficult to know which clients will decide to short-circuit a plan. Blanchett says advisors should build that uncertainty in.

“Financial planners,” Blanchett says, “should consider modeling early retirement to prepare clients for the (likely) possibility that it may occur, especially for those targeting a retirement age past age 65.”

To avoid disaster, planners should be in frequent communication with their clients, professionals say. They should start imagining the worst outcomes in the decade or so before the client retires.

And the clients should not rely on Social Security to bail them out of an underfunded plan. One recent survey suggests that even though some clients are becoming more skeptical of the program, they are also becoming overdependent on it.

“Most workers are concerned about Social Security, but they are also counting on Social Security as a meaningful source of income in retirement,” said Transamerica in a retirement survey.

Advisors often say they try to correct for this overconfidence by underestimating what clients will get out of the program.

Open Channels Of Communication

Anthony Ogorek, a certified financial planner in Buffalo, N.Y., says that advisors should meet frequently with clients who are 10 years out from their target retirement date. This will help everybody avoid a blowup.

“A plan shouldn’t be a static document. It must be updated frequently based on circumstances,” Ogorek says. “It’s like illness and going to a doctor. If you see the doctor on a regular basis, then you are more likely to catch the problem.”

He says advisors should be frank with clients—and tell them that a changed retirement date will change the assumptions of the plan and dramatically alter people’s expectations about how and when they can stop working.

“Maybe someone needs to work longer or maybe someone will need to have a lesser lifestyle in retirement,” he says.

If the client relationship is good, the channels of communication should already be open, Ogorek says, and that will stop problems before they occur.

But many clients aren’t updating their advisors, or advisors aren’t pushing for enough meetings.

The current outlook for many Americans meeting their retirement goals is “bleak,” Wendel says. “The only thing that can happen in some cases is changing the standard of living in retirement. And that can be scary.”

In his study analyzing which clients can and cannot achieve retirement goals, he makes certain assumptions: that the average client has no massive debt, that he or she won’t require high standards of living in retirement, and that there will be no cuts in Social Security.

Despite those assumptions, he estimates only some 25.6 percent of currently working households are “on track to have what they need in retirement.”

Even the rich have problems, Wendel says, adding that only about 50 percent of mass-affluent households will achieve their retirement goals.

But he emphasizes that the situation doesn’t have to be bleak if clients can receive good advice in a timely manner and the advice includes multiple strategies.

Delaying retirement can be a good option, he says. But it’s also effective if clients simply contribute more to a plan—say 6 percent instead of 3 percent—and accept a lesser standard of living in retirement.

It makes a big difference if advisors can work closely with clients and make them understand the nature of the savings gap.

“If you can begin early on, then you are going to have more options,” Wendel says.