If you are on a payment plan from a previous tax debt, the IRS will automatically keep any new tax refund and apply it to the past debt. This does not reduce your monthly payment amount or change your payment schedule, but will reduce the total number of remaining payments.
If you are now paid in full (or overpaid) as a result of the monthly payment plus refund, the IRS will send you a check for the difference, probably in about 3 weeks.
