Installment Agreement
An Instalment Agreement is a United States Internal Revenue Service (IRS) program that allows individuals to pay tax debt in monthly payments. 

There IRS has several different kinds of Instalment Agreements; Guaranteed, Streamline, Partial and Full Pay. There are a number of requirements that have to be met before an instalment agreement can be granted to a tax payer.

Requirements 
 Has to file all minimum required tax returns.
 Must owe $50,000 or less. 
 Monthly payment cannot be less than $25 a month.
 Keep a check on future refunds that can applied for tax refunds until tax debt is paid in full.

References 

Internal Revenue Service