As you explore your retirement account options, you will soon discover that all IRAs, whether traditional or nontraditional, must be held and supervised by a custodian. An IRA custodian works as the bank for the retirement account and is highly regulated by the IRS and state and federal banking commissions. Custodians have to meet stringent federal requirements in order to keep their good standing. In most cases, custodians or trustees also serve as the administrator for the account.