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Tax Change Implemented Pay Period (PP) 2024-09: IA and MT

MEMORANDUM

DATE: April 25, 2024
TO: Federal Personnel and Payroll System User Group Representatives
FROM: Lisa J Puente, Deputy Chief, Payroll Operations Division
SUBJECT: Tax Change Implemented Pay Period (PP) 2024-09: IA and MT


Please share this information with all impacted employees. The following tax changes were implemented in PP 2024-09. As a reminder, tax changes are not retroactive to employees’ withholdings.

State Taxes

  • Iowa Income Tax Withholding:
    • The state income tax withholding formula has changed effective January 1, 2024.
    • The state has implemented an annual total withholding allowance. This allowance is a fixed annual dollar amount and is claimed on line 6 of the Form 2024 IA W-4, Employee Withholding Allowance Certificate.
      • We highly encourage employees to submit a new 2024 IA W-4 to ensure that their state withholdings are accurate. 
    • The rate table has changed.
    • Datamart Query: Tax State = 19
  • Montana Income Tax Withholding:
    • A reduced designated PP withholding amount has been added to the state's revised Form MW-4, Montana Employee’s Withholding and Exemption Certificate. The tax formula has been updated to allow for a fixed PP withholding amount that may be less than the amount required based on the state's standard formula.
    • Datamart Query: Tax State = 30

You may execute Datamart queries to identify employees in affected state taxing areas. For Combined File Ad-Hoc query/analysis of applicable States: add STE Tax State 1 = (State Code above) or STE Tax State 2 = (State Code above) to the filter or prompt lines. Another option is the shared Datamart report titled “State Tax Code Report” (State Tax Code Query Now Available).

The Interior Business Center (IBC) Payroll website is updated frequently; you may view the state tax formulas here: Federal, State, and Territorial Income Tax Withholding Formulas.

If there are any questions, please call the IBC Customer Support Center at 1 (866) 367-1272 or by email at Payroll_Helpdesk@ios.doi.gov.