Calculating the Iowa income school district surtax is not complicated. Under Iowa law, any resident earning a net income over $9,000 or a married couple filing a joint return earning a net income over $13,500 must file an Iowa income tax return. The county and school district where the taxpayer resides determine the income school district surtax rate to be charged to the taxpayer's income. The Iowa income school surtax is a local option tax adopted upon voter approval for the purpose of funding educational improvement programs in a school district.
You can use Iowa's county surtax tables to find the specific portion of your taxable income that will be allocated to school districts.
Calculating Your Taxable Income
Calculate your Iowa taxable income on Form 1040. Subtract the amount determined from Line 41, your standard and itemized total deductions, from the amount determined on Line 36, the portion of your income subject to taxation.
Determining How Much Tax You Owe
Calculate your Iowa income tax owed. Add your Iowa income tax liability to any Iowa lump-sum tax owed and any Iowa minimum tax owed to determine the total amount of taxes you owe. Subtract from Line 46, the total tax you owe, all credits you can claim. If you qualify to receive a nonresident or part-year resident credit, or some other nonrefundable Iowa credit, subtract these credit amounts as well from your total taxes owed.
Locating Your Surtax
Locate the Iowa income school district surtax rate that applies to the county and school district where you reside. Your applicable school district and county for tax purposes is the one in which you resided on the last day of the tax year. You can view this information online at the Iowa Department of Revenue website. For instance, in 2017 a resident of Butler County living in the Nashua-Plainfield School District would have been charged a school income surtax rate of 09 percent.
Adjusting for Credits
Multiply the Iowa income school district surtax rate by the your Iowa total income tax liability minus any credits you claimed. For instance, if you had a total Iowa income tax liability of $3,333 and you lived in the Nashua-Plainfield School District, which has an 9 percent income surtax, you would owe $299.97. To do this calculation, multiply the Iowa state income tax amount due, $3,333, by 0.09 to arrive at your Iowa income school surtax of $299.97.
Completing Your Paperwork
Add your Iowa total income tax liability, Line 54, to your income school district surtax taxes owed, Line 55. Record this information on Line 56 of your 1040 form.
Pedro Carrasquillo began writing professionally in 2002 while working for the New Jersey state legislature. He coauthored the legislature's annual "Budget Analysis for the Department of Community Affairs" from 2002-07. Carrasquillo holds a Bachelor of Arts in comparative literature from Haverford College as well as a Master of Science in public policy and management from Carnegie Mellon University.