A trust fund, on the scale of this web site, is a pretty simple concept. You set aside money for someone else, it grows over a number of years (based on appreciation / depreciation and additional contributions) and at some point, the person receives the money. In Illinois, the beneficiary receives the money "free and clear" at the age of 21.
Each trust fund has a CUSTODIAN and a BENEFICIARY. The Custodian sets up the trust fund, makes contributions, and manages the investments. If you have withdrawals before the beneficiary takes over the money, the custodian determines how much of a withdrawal to make and if the purposes are valid given the objectives of the trust (i.e. pull money out to use for college tuition). Due to the fact that my nieces and nephews are young and we are just getting started, we haven't considered any withdrawals yet.
Each trust has a TRUSTEE. The trustee is a third party that holds the funds. Note the word "irrevocable" in the definition above - when you put the money in a trust and the trustee holds it, you can't change your mind later and get the money back out of it. Typical trustees are banks and investment institutions like Fidelity or Vanguard.
At some point the beneficiary takes over the fund and can do what they please with the proceeds. If the stakes are higher (i.e. lots of money), then people anguish over how to control the behavior of the beneficiary so that they don't "blow" the proceeds (i.e. spend it on a "bouncing car"). For our purposes, however, we are not going to put strings on what the beneficiary does with the money after it legally transfers over to them, because while the stakes are important, this much money won't fundamentally alter someone's life. Plus, a UGMA / UTMA account won't let you put any strings on it, anyways. The age of "termination" is the official definition of the date when the minor takes control.
Trust fund rules vary by state. Some states have something called a UTMA, as opposed to the UGMA in Illinois. The biggest difference is the age when the beneficiary takes over for the trustee, which is 21 in Illinois and 18 in other states. There are other differences but if your situation is that complex don't get advice from this site, see a lawyer :)
In summary, the key points are:
A TRUSTEE holds the securities (usually a bank or a brokerage house like Fidelity or Vanguard)
The CUSTODIAN sets up the trust, puts cash / investments into the trust, manages the investments, and decides whether or not to make withdrawals on behalf of the beneficiary
The custodian has a FIDUCIARY RESPONSIBILITY to manage the money in a prudent fashion for the beneficiary (i.e. don't invest in some crazy scheme)
Deposits in a trust are IRREVOCABLE and cannot be reversed if you change your mind later
The BENEFICIARY is the person who ultimately takes over the cash / investments that have been deposited in the trust. For the purposes of a UGMA / UTMA account, the beneficiary is always a minor
The AGE OF TERMINATION is when the minor takes over control of the trust - this varies by state, but is 21 in Illinois (it is 18 in other states)
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I just realized that the above description makes it sound more exciting that it is.
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