Fringe benefit (FB) rates are expressed as a percentage of salary. Separate FB rates are used for federal and non-federal grants and contracts, and those rates are divided by faculty/monthly employees, bi-weekly employees, Ph.D. students and other students. (The rate for students is only to be used when a student is not currently enrolled.) Federal rates are lower as a result of the government's decision to end participation in the tuition reimbursement portion of Duke's FB program.

Duke's FB rates are negotiated with DDHS; however, the negotiated rates usually cover only one fiscal year at a time. The University's Corporate Controller projects FB rates several fiscal years in advance. Unless the Sponsor stipulates otherwise, faculty are expected to use the projected rates when preparing proposals. The Controller's office notifies the faculty and ORS of changes in the projected rates. Current and recent past rates are available on the Financial Services website.

The budget periods in a proposal do not always correspond to fiscal years. A given budget period may include more than one fiscal year and, therefore, more than one fringe benefit rate would be applicable to that period. The method for resolving this issue depends upon the sponsor and the anticipated award mechanism. If the award will be a grant, federal or non-federal, it is usually acceptable to use the fringe benefit rate which would apply to most of the proposed budget period. If the award will be a contract, the sponsor may require that each month of the budget period carry the correct rate.