A shack in the boondocks _ that’s about the value of the average inheritance in the coming transfer of wealth from baby boomers to their progeny. But that doesn’t diminish the challenges faced by people coming into money.

Overall, $42 trillion to $136 trillion is expected to pass between generations, according to Boston College researchers Paul Schervish and John Havens. But that shakes out to an average of $90,000 per heir.

Heirs may receive conservative portfolios focused on income at an age when a growth strategy might be more appropriate. This often means selling bonds to buy stocks, a move that only incurs capital gains taxes if the values rise after the decedent’s death.

“An inherited portfolio might lack proper diversification or might not match the heir’s risk profile,” says Robin Tull, a Norfolk, Va.-based financial planner.

Given the average windfall’s value of $90,000, it’s very likely that a significant portion will come from a home, retirement plans or even deferred annuities. Each of these has a different set of consequences that may surprise the beneficiaries.

Retirement plans and annuities don’t qualify for the inheritance tax exemption. This is currently capped at $1.5 million, will increase annually to $3.5 million in 2009 and without a congressional extension would return to $1 million in 2011. But this doesn’t apply to all types of investment accounts.

“IRAs weren’t intended to be inheritance vehicles, they were intended to be retirement vehicles,” explains Mark Luscombe, principal tax analyst at CCH, a publisher in Riverwoods, Ill. “You escape tax when contributing to an IRA, so people who inherit IRAs are essentially paying their parents’ taxes.”

But the IRA plans don’t bother explaining this to the beneficiaries, nor advise retirees to move the assets into trusts for easier transmission to heirs.

“You see a lot of bad information given to people with these plans,” says Robert Clofine, an estate tax lawyer in York, Pa. “When the institution tells the heirs they are beneficiaries of an IRA or annuity, the beneficiaries don’t know that they have options that are less taxable than taking the full payout right away.”

To defer taxes and gain liquidity, an inherited IRA can be put into a trust and then drawn down annually _ federal law requires a minimum yearly payout of $20,000 that is taxed as income.

An inherited annuity can be even trickier. The instruments might resemble bonds, mutual funds and insurance, but the monthly payments from the issuers are cash _ easily spent and taxed as income.

“Don’t just put it in a checking account, because it will be spent. Set up a brokerage account,” says Tull. “Some issuers offer to set up a money market fund for the monthly annuity payments. That’s a strategy for the insurance company (issuer) to keep the money, at least until the heir decides what to do with it.”

Meanwhile, homes qualify for the inheritance tax exemption as long as the heir retains the property _ sell it and a capital gain is incurred on the difference between the value of the home at death and the sale date.

Such taxes can seem contradictory, if not unfair, to an heir who might be relatively inexperienced with real estate and investments. “There can be confusion there in associating these capital gains with income taxes,” says Guy Cumbie, a certified financial planner in Fort Worth, Texas. “To avoid these taxes, sell the assets right at the day of death, or simply keep the house.”

Another big surprise is debt, which gets passed on along with the assets and netted out. Creditors can make claims upon an estate until the will closes and can do so in probate court if push comes to shove. But while assets are often discussed with heirs ahead of time, the opposite usually applies to debt, since people generally tend not to talk about losses of any kind.

People are equally tight-lipped about trust funds, a silence underscored by the fact that tied-up assets are in the minority. Such inheritances come with a surrogate parental figure in the guise of a trustee who is usually some form of financial planner.

Woe to the heir who doesn’t get along with said guardian, because it’s nearly impossible to change trustees.

“The problem has been that the people who set up these things don’t really know how they’re managed. There’s no educational booklet, and the beneficiaries don’t know what their rights are,” says Standish Smith, founder of Heirs Inc., a group devoted to trust and estate law reform. “Corporate fiduciaries like it that way because if the beneficiaries find out, then they can sue. Bankers think their real clients are the deceased, and that the beneficiaries are risk factors.”

Without a trust, inheritors of estates worth at least six digits get to decide whether to stick with the decedent’s financial planner. Hit the midpoint between six and seven digits, and the family accountant and lawyer come into the picture. Make that seven digits, and a whole team of advisers arrive on the scene.

Presumably, most of these experts have good intentions _ after all, the decedent chose them _ but they can seem like predators to the uninitiated, especially because their fees escalate along with the amount of bureaucracy involved in closing the estate.

“Your parents’ lawyer or accountant is basically still serving the parents, and after they die these advisers might still consider you a little kid. And if you’re not comfortable with that, you need to find someone you can trust,” says Dan Rottenberg, author of “The Inheritor’s Handbook: A Definitive Guide for Beneficiaries.” He advises checking prospective advisers’ credentials and whether they’ve been cited for violations by the National Association of Securities Dealers, Inc.

Many of these experts advise the heirs to continue working, even if they are among the few who inherit enough money to warrant an early retirement.

Leaving the work force ahead of peers can lead to boredom and even self-esteem issues, says Thayer Willis, a therapist who specializes in new wealth. Willis cites society’s prevailing work ethic as a factor.

Newly wealthy people may also see strains on their personal relationships. Even friends become fair weathered, asking for handouts and not paying them back. And often a sense of isolation sets in, since the heir may feel estranged from those who haven’t gotten such windfalls.

This phenomenon inspired author Joanie Bronfman to coin the term “wealthism” in “The Experience of Inherited Wealth: A Social-Psychological Perspective.” “Wealthism includes those actions or attitudes that dehumanize or objectify wealthy people, simply because they are wealthy. The main attitudes of wealthism are envy, awe and resentment. Wealthism differs from the other `isms’ in that racism and sexism are perpetrated by those who have power, whereas wealthism is directed at those who have power.”

Such problems may be ones that most people would be lucky to have, but that’s because most people won’t be inheriting more than enough money to pay off their debts and go on a shopping spree. A little self-indulgence can be a healthy way to come to terms with any amount of new money.