A Share Certificate, typically known as a CD, is an account that offers a higher interest rate, but is locked in for a specified length of time.  At City of Boston Credit Union, these accounts deliver the highest yield in exchange that funds remain on deposit until the specified maturity date and only require a minimum deposit of $500. "Jumbo" certificates are also available with a minimum balance of $50,000 paying higher yields than regular term certificates with the same maturity. The terms on a Share Certificate Account range from three months to 5 years with a penalty imposed for early withdrawal.