maintenance margin requirement investment & finance definition

The minimum equity in an account as a percentage of the value of the account. For example, if the maintenance requirement is 25%, the account equity (the market value of the securities minus the amount owed) must equal at least one-quarter the value of the securities in the account. The maintenance margin requirement becomes important when securities purchased on margin fall in price. Also called margin requirement, minimum maintenance. See also house maintenance requirement, initial margin requirement.