According to Zacks.com, a variable-rate IRA has an interest rate that changes throughout the life of the IRA, unlike traditional IRAs in which the interest rate is fixed. These rates can change monthly or as frequently as daily and are usually determined by U.S. Treasury security rates.
Variable-rate IRAs are typically 18 months, according to Zacks.com. When the IRA matures, the holder can move the IRA to a different bank, renew the IRA or withdraw money. Usually, variable-rate IRAs have minimum deposits of between $5 and $100, while a fixed-rate IRA may require a minimum deposit of $500 or more. Additional deposits may be made to variable-rate IRAs until they mature without penalty.