NEW YORK (MainStreet) — Parents aren't talking to their kids about the cost of getting a college education, and that could spell big trouble.

According to a new survey by the financial literacy prep course Junior Achievement, there is an enormous expectations gap between parents and teens when it comes to who will be paying for college. Nearly half of all high school students expect that their parents will pay their tuition.

Only 16% of those parents agree.

The result is a sort of slow-rolling disaster, with high school students often ignorant and unprepared for the financial realities waiting for them on the other side of graduation. Families could deal with this up front, recommended Junior Achievement President Jack Kosakowski, except that it touches on a taboo subject. Parents, in his experience, would rather talk to their kids about sex than money.

"The theme of this is with parents and their kids there's really a disconnect," Kosakowski said. "Kids and parents simply aren't talking about funding their college education. To me that's really troubling."

He called the tuition disconnect part of a bigger challenge, that families avoid teaching children about money and budgeting in general. Indeed, in many families, the parents themselves may need a refresher on the subject. Without proper education they have often made embarrassing mistakes, and are reluctant to share those experiences with their children.

Now, there is some good news. Junior Achievement's survey studied the expectations gap between parents and children about full freight tuition, meaning that many more parents may have plans to make some contribution to their child's education. The problem is that this information often comes too late. When money has become an awkward subject parents might hesitate to raise the issue until the last minute, when the family has gathered to celebrate a stack of acceptance letters… and then break the bad news.

It's a problem that plays out every spring in the office of Jim Brooks, the University of Oregon director of financial aid and scholarships. It's a particularly heartbreaking scenario: students fall in love with their school of choice, he explained. To learn that they can't attend because of money is painful, especially after the thrill of acceptance and planning a college career along with all their friends.

Those students are nothing, however, compared to the students who have to leave school mid-year because the talk comes after enrollment.

"You have the parents that refuse to say to their son or daughter, 'we can't afford to send you there,'" Brooks said, "and after a term or two they realize that this isn't going to work out. By then their son or daughter has gotten attached to the school and they have to pull them out, because they can't afford to keep them there."

For parents, the problem is often preparation. Some families haven't saved or started saving too late, and they can't afford college tuition on what they have available. These parents may often avoid talking to their children out of reluctance to admit that mistake, pushing off the issue until they can't avoid it any longer.

For other families the reality of college costs come as a surprise. "I've had conversations with parents and students who were totally surprised," Brooks said, not because they didn't know the numbers but because they had convinced themselves that it would all somehow work out.

He tells the story of one family that had to rebuild its college plans, because the parents believed that their son would get scholarship money. Only one school offered him anything, awarding $5,000 to attend a $60,000 school. It was nowhere even close to enough.

Some families try to negotiate, convinced by friends and financial counselors that colleges will bargain over their prices. Public schools don't have the luxury of negotiation, Brooks said.

Private schools rarely want to.

Students can sometimes get help. The ones who need to close a relatively small gap can apply for financial aid or take out loans, while others who simply need money to make the rent can find a campus job.

Those cases are the good ones. The difficult conversations, Brooks said, are students who come in looking to cover most of their tuition. For them the math often just doesn't work. The day is long past when a student working the average 10 to 15 hours per week can make even a meaningful contribution to a college tuition, and student loans can only help so much.

Federal loans for an undergraduate max out at $5,500 per year. "If they're a non-resident student looking at a school out of state, that's just a drop in the bucket," Brooks said.

It's why the money conversation is so important ahead of time. Students need to know what schools they can afford before they begin looking, otherwise it becomes far too easy to arrive on campus hopeful, excited and empty-handed.

For the empty-handed students, accepted but desperate, Brooks said that "usually by the time we're having that conversation there's not a lot that I can do to help them."

What can families do to avoid this problem? Kosakowski advised the simple remedy of ripping off the bandage: just talk. Parents need to bring this subject up with their children, from college tuition all the way down to the little stuff.

They might even be surprised to learn that their children aren't surprised at all. With college costs skyrocketing past $50,000 per year, high school students are well aware that many schools have priced themselves out of reach for the average family.

And if they're not, they need to be.

-Written for MainStreet by Eric Reed, a freelance journalist who writes frequently on the subjects of career and travel. You can read more of his work at his website A Wandering Lawyer.