What does Next Maturing Amount on an IRA mean?

I assume you are talking about a bank IRA CD? Brokerage IRA don't mature or have a maturity date like bank IRA CD's. In bank IRA CD's, the maturing amout would be the amount deposit when the CD was open and the accrued interest that the CD has earned from opening time to maturity date (i.e 1 years, 2 year, etc). If you take the amount out before maturity date, then there would be a penalty that the firm which holds that CD would deduct from the current CD amount (amount deposit + the interest that has already been earned).