Not all taxes are created equal. Review important information about federal, state and supplemental income taxes.

Federal taxes

Only current employees who want to change their withholdings, those who filed as tax-exempt in the prior tax year, and new hires need to submit a W-4 to CU. 

  See the self-service W-4 webpage for full instructions

Helpful resources

Ensuring that the right amount of tax is withheld from your pay is an important part of preventing an unexpected bill or penalty during tax season.

 Use the IRS Tax Estimator to help determine your withholdings. Get started by gathering your most recent paystubs, income tax return and W-2s. If your personal circumstances change during the year, revisit the estimator to ensure withholdings are still correct.

State taxes

The University of Colorado withholds state taxes from the state in which you perform work. Make sure your withholdings are correct by submitting your state’s W-4. 

  Submit your form

Supplemental income taxes

If you receive certain forms of compensation beyond your regular salary, it may be taxed. This can include, but is not limited to, bonuses, severance payments from termination of your employment, some prizes and awards, reimbursements of nondeductible moving expenses and more. The rates at which specific earnings are taxed are determined by IRS and individual states.

The current federal tax rate on supplemental wages is 22% and Colorado’s rate is 4.4%. Learn more about specific taxable supplemental incomes below.

Taxable supplemental income types

Earning Code


Eligible Employees

CU 401(a) Eligible

PERA Eligible
401K, 403B, 457 Eligible

ADP Additional Pay - Student/Med Res Students
Medical Residents
N/A N/A Yes Additional pay due to student employee or medical resident.
APF Additional Pay Flat Amount Faculty
University Staff
Classified Staff
Yes Yes Yes To be used for additional pay of a flat amount for additional work or services. Payment request for classified staff should be referred to Human Resources. Documentation is required.
AWR Awards - Taxable All No No Yes Recognition/award programs must be preapproved by appropriate campus entities (Human Resources, Provost, Vice Chancellor, Org Principal) in accordance with PSC Procedural Statement: Recognition and Training.
BON Bonus Faculty
University Staff
Classified Staff
No No Yes Paying employee bonuses. Additional documentation is required.
INC Incentive Pay Faculty
University staff
Yes Yes Yes Additional documentation is required with this request.
LSA Legal Settlement
No Retirement
All No No No Legal settlements are not 401(a) or PERA eligible.
MVT Moving Expense - Taxable Faculty
University Staff
No No No Payment for taxable moving expense reimbursement and moving expense flat allowance.
REC Recruitment Incentive Faculty
University Staff
No No Yes To pay recruitment incentive amounts. This must be documented in offer letter. 
REF Referral Award Classified Staff No No No Additional documentation is required with this request.
SEV Severance Faculty
University Staff
No No No To be used to issue severance pay.
UOC UPI On-Call Incentive Faculty Yes Yes Yes To pay CU Medicine (formerly University Physicians, Inc.) on-call incentive amounts. Limited to job code series 1100 and 1200 only.
UPI UPI Incentive Payment Faculty and Officer
University Staff
Yes Yes Yes To make a payment to an employee that is provided by CU Medicine (formerly University Physicians, Inc.).  Additional documentation is required with this request.