Maximum Rate

Absent an appropriations authority which authorizes pay at a higher rate, the daily rate paid an expert or consultant appointed under 5 U.S.C. 3109 may not exceed the unadjusted rate for GS-15, step 10.

Daily Rate

When an expert or consultant is being paid a daily rate, the daily rate may not be changed to an hourly rate for any purpose. The daily rate (no less and no more) shall be paid regardless of the number of hours the expert or consultant works until the contract expires or the appointment changes. 

Since most experts and consultants are hired on a temporary basis and work more than 8 hours a day, the daily rate is usually advantageous to management since the individual does not incur an overtime entitlement.

Annual Basis

An expert or consultant who is paid on an annual basis may not exceed the unadjusted rate for GS-15, step 10, on a daily or biweekly basis. If paid a locality rate and/or overtime, an expert's or consultant’s aggregate pay may not exceed the unadjusted rate for GS-15/10 on a daily or pay period basis.

Premium Pay

Premium pay may not be paid unless the contract provides for premium pay. A contract notwithstanding, overtime may not be paid if the expert or consultant is paid on the basis of a daily rate (see the paragraph above). However, nothing in regulation precludes an expert or consultant's being paid the daily rate for six consecutive days, e.g., for work in excess of 5 days in a week.

Compensation Waived

When compensation for a class of positions is not fixed by statue, e.g., pay of consultants and experts under 5 U.S.C. 3109, the individual may waive payment. Unpaid service may be accepted only when the individual has a special interest or special qualifications for the position, service is part-time or intermittent and lasting only for a few weeks, and the individual executes a waiver of future claim against the government. 

Reference

5 U.S.C. 3109