Installment Agreement
If you cannot pay the full amount due with your return, you can ask to make monthly installment payments for the full or a partial amount. However, you will be charged interest and may be charged a late payment penalty on the tax not paid by the date your return is due, even if your request to pay in installments is granted. If your request is granted, you must also pay a fee. To limit the interest and penalty charges, pay as much of the tax as possible with your return. But before requesting an installment agreement, you should consider other less costly alternatives, such as a bank loan.
Internal Revenue Pub 17