When most people think about trust funds, they envision spoiled rich kids and wealthy families trying to dodge taxes on their piles of money.

But what they might not realize is that trust funds can be an incredibly useful—even vital—tool for middle class families, as well.

A trust isn’t a financial instrument like a 529 plan or a retirement account. Strictly speaking, a trust isn’t a kind of account at all—it’s a legal entity that lets you put assets on hold for another party. A document designates how the contents of the trust will be distributed, to whom (the “beneficiary”), how those contents may be used and who is responsible for that distribution (the “trustee”).

“During your lifetime, a trust is like your shadow or your buddy following you along,” says Lorrie Minor, a Certified Financial Planner™ with LearnVest Planning Services. “You can treat the trust as an entity, like yourself—it can get paid, pay other people, and function as a financial body, but it isn’t an account type. If you want to find the best vehicle for your financial life, and for your heirs, your safest bet is to speak to an estate planning attorney.”

So a trust is your shadow—but do you really need one? Read on to learn more about the ins and outs of trusts, and how to start figuring out whether one is right for you.

How Should You Set Up a Trust?

While there are many kinds of trusts, the most common type allows the person who establishes the trust and contributes its contents (the “grantor”) to be both the beneficiary and trustee during his or her lifetime. This is called a living revocable trust, because it can be changed while he or she is alive. When the grantor dies, the trust becomes irrevocable, or unchangeable.

When you have money in a nonretirement account like a brokerage account, you have the option of making that account “transfer on death,” or TOD, which means you fill out paperwork at your bank or brokerage that enables your account to transfer to a beneficiary automatically upon your death, bypassing the otherwise-mandatory legal process called probate. If your accounts don’t have transfer-on-death measures established, that money has to go through probate, will or no will, and the information in that process can be released to the public. By putting money in a trust, the trust automatically bypasses probate and the details are kept private.

Despite the recent availability of user-friendly trusts you can set up online, “an adviser will lead you to what’s best for your situation, versus a cookie-cutter trust built for the masses,” says Lou Karol, an estate planning attorney based in Long Island, New York. Minor agrees: “Personally, although I have been practicing financial planning for 20 years, I would definitely consult an attorney for more complex situations,” she says.

Unsure if a trust is right for your family? Here are some reasons you might consider creating (also known as “executing”) a trust:

1. You Don’t Want Your Kids to Inherit at Age 18

You don’t have to be loaded to have some assets to pass on to your loved ones. Between a home, a life insurance policy and regular savings, you might have more assets than you think, says Minor. In most cases, when you’re setting up a will or estate, your spouse is typically the first person to inherit your assets if something happens to you. But if, heaven forbid, something happened to both of you at the same time, your children might be the next in line to inherit.

By default, your child would get everything at once, usually at age 18 (depending on where you live). “But many parents are averse to their children inheriting significant assets outright at age 18, so a trust allows you to state not only who should inherit, but when they should inherit those assets,” Minor says. “Some parents choose staggered distribution dates for a great number of reasons … some parents might like their kids to inherit something at 18, something at 30 and something more at 40, for example.”

2. You Want to Protect Against Creditors

“Typically, a middle-class family sets up a trust for the protection of a child from creditors and predators,” says Karol. A child might have a house that’s underwater in this economy, or credit card debt, or might be living hand-to-mouth. If your child came into a large sum all at once, creditors could try to reach for that amount,” Karol says. “If you set up a trust and that child gets the money in a trust,” he says, “that inheritance is protected.”

Beneficiaries who are good candidates for this type of protection include those in professions with a lot of liability, Karol says, like doctors, lawyers, architects or those in the construction industry. It also includes those with many outstanding personal debts or who have borrowed significantly to start a business and are not sure yet whether they’ll be able to pay back the full amount. “You don’t want to put the inheritance at risk,” he says.

3. You Want Someone Else at the Helm

You decide who inherits your estate based on love, not financial acumen. But what if your beloved beneficiary isn’t great with money?

For instance, your beneficiary might demonstrate poor decision-making or be susceptible to outside influence when it comes to financial decisions. “You might want a trust if your child is in a poor marriage,” Karol says. “More times than not, inheritance is considered separate property, meaning it wouldn’t be subject to the rights of the spouse in case of divorce, but when people go through a divorce they sometimes lose their mental compass and make bad decisions.” If, for example, someone is trying to save his marriage by giving or lending money to his spouse, a trustee or co-trustee would be in a position to provide external guidance and talk him out of it, Karol says.

Minor adds, “Sometimes a trust has a provision called a ‘spendthrift provision’ that limits the beneficiary’s access to the money if they are prone to excess or extravagant spending.”

Or, if your beneficiary isn’t good at investing, you could name an investment trustee in the trust documents, and that person will be responsible for investment decisions, Minor says.

If you create a trust with an experienced lawyer, you can tailor it to all eventualities. For example, the conditions may state that the beneficiary can fire the trustee if he turns out to be unreliable, but can only replace him with an unbiased, independent trustee, rather than, say, a boyfriend or husband who has a vested interest in the money.

4. You Have a Complicated Family Situation

“This is something that comes up quite frequently for families of remarried couples who have children,” Minor says. For example, if you and your spouse both have children from previous marriages, you might create a trust to make sure your spouse is O.K. if you predecease him or her but also provide for your children.

“Often, trusts will say, ‘I want my surviving spouse to be able to take out or distribute assets from the trust for health, maintenance, support and education—they can withdraw under certain circumstances. But upon the death of the spouse, the assets go to a certain named person,” Minor says. “My father passed away and his assets were available to my stepmother to the extent she needed them, but if she doesn’t need the assets, then the remainder of the trust goes to all my dad’s children, not her children.”

5. You Want to Avoid the Probate Process

Certain assets transfer to descendants without major issue. “If you hold something jointly, designate a beneficiary or have a bank account instruction like a transfer-on-death account, all of that isn’t included in the probate process,” Minor says. But for everything else, including real estate assets, there’s no shortcut to smooth over the inheritance process. You can say in your will whom you’d like to inherit, but the estate will still go through probate. For example, if your mother leaves you a house in her will, but not in a trust, it will have to go through probate. If that house is in a trust, however, it will transfer without going to court. “You have to have an attorney, go to court, and that could take time,” she says. “It’s a painful time for family members, so a lot of people prefer to just dump everything in the name of a trust and have it administered that way.”

6. You Want to Take Care of a Disabled Child

If you have a child with special needs, you might need to think about ways for her to inherit your estate without losing government benefits like Medicaid or Social Security. “Special trusts allow disabled children to stay on government benefits, while having a trust established to pay for special care or special needs not covered by government programs,” Karol says, “like extra clothing, trips with other family members, buying a TV, things like that. For instance, maybe the trust could help afford a better wheelchair than what the government would supply.”

7. You Want to Safeguard Your Privacy

This probably doesn’t apply unless you’re a celebrity or have secrets you don’t want spilled, but Minor notes that wills become public after a person’s death, whereas trusts are private documents. “When Jackie O. passed away, she had a very simple will that made some ‘public stipulations’ that would be shared with the public, but as for all the rest of the details, no one knew because it was included in her trust,” Minor says.

LearnVest Planning Services is a registered investment adviser and subsidiary of LearnVest, Inc. that provides financial plans for its clients. Information shown is for illustrative purposes only and is not intended as legal or investment advice. Please consult an attorney or financial adviser for advice specific to your legal or financial situation. The people quoted in this piece are not clients of LearnVest Planning Services. LearnVest Planning Services and any third parties listed in this message are separate and unaffiliated and are not responsible for each other’s products, services or policies.