TAXES 18-30, Iowa State Income Tax Withholding

Published: March 21, 2018
Effective: Pay Period 06, 2016

Summary

This tax bulletin is being updated to remove the number of pay periods in steps 4, 5 and 9 and replace with the phrase "number of pay dates in the tax year," thereby preventing any confusion in future years. All other information in this bulletin remains the same.

No action on the part of the employee or the personnel office is necessary.

Tax Formula

State Abbreviation:

IA

State Tax Withholding State Code:

19

Acceptable Exemption Form:

IA-W4 or W4

Basis for Withholding:

State Exemptions

Acceptable Exemption Data:

0/Number of Allowances

TSP Deferred:

Yes

Special Coding:

Determine the Total Number Of Allowances Claimed field as follows:

  • First Position - Enter 0 (zero).
  • Second and Third Positions - Enter the number of allowances claimed.

Additional Information:

None

 

Withholding Formula (Effective Pay Period 06, 2016)

  1. Subtract the nontaxable biweekly Thrift Savings Plan contribution from the gross biweekly wages.
  2. Subtract the nontaxable biweekly Federal Health Benefits Plan payment(s) (includes dental and vision insurance program and Flexible Spending Account - health care and dependent care deductions) from the amount computed in step 1.
  3. Add the taxable biweekly fringe benefits (i.e., taxable life insurance) to the amount computed in step 2 to obtain the adjusted gross biweekly wages.
  4. Multiply the adjusted gross biweekly wages by the number of pay dates in the tax year to obtain the gross annual wages.
  5. Multiply the biweekly Federal income tax withholding by the number of pay dates in the tax year to obtain the annual Federal income tax withholding and subtract this amount from the gross annual wages computed in step 4.
  6. Determine the standard deduction by applying the following guideline and subtract this amount from the result of step 5 to compute the taxable income:

    If the Number of Allowances Claimed Is:

    The Standard Deduction Is:

    0 or 1

    $1,650

    2 or more

    $4,060

     

  7. Apply the taxable income computed in step 6 to the following table to determine the Iowa tax withholding:

    Tax Withholding Table

    If the Amount of Taxable Income Is:

    The Amount of Iowa Tax Withholding Should Be:

    Over $0 but not over $1,300

    0.36%

    Over $1,300 but not over $2,600

    $4.68 plus 0.72% of excess over $1,300

    Over $2,600 but not over $5,200

    $14.04 plus 2.43% of excess over $2,600

    Over $5,200 but not over $11,700

    $77.22 plus 4.50% of excess over $5,200

    Over $11,700 but not over $19,500

    $369.72 plus 6.12% of excess over $11,700

    Over $19,500 but not over $26,000

    $847.08 plus 6.48% of excess over $19,500

    Over $26,000 but not over $39,000

    $1,268.28 plus 6.80% of excess over $26,000

    Over $39,000 but not over $58,500

    $2,152.28 plus 7.92% of excess over $39,000

    Over $58,500

    $3,696.68 plus 8.98% of excess over $58,500

     

  8. Determine the exemption allowance by applying the following guideline and subtract this amount from the results of step 7 to compute the annual Iowa tax withholding:

    Exemption Allowance = $40 x Number of Exemptions

  9. Divide the annual Iowa tax withholding by the number of pay dates in the tax year to obtain the biweekly Iowa tax withholding.

Resources

To view the updated tax formula, go to the HR and Payroll Clients page from the MyNFC drop-down menu on the National Finance Center (NFC) homepage. Select the Publications tab and select U.S. Income Tax Formulas from the Publications menu to launch the tax map. Select the desired State from the map provided for the formula.

Previous Tax Bulletin

Inquiries

For questions about NFC processing, authorized Servicing Personnel Office representatives should contact the NFC Contact Center at 1-855-NFC-4GOV (1-855-632-4468) or via the customer service portal.