40 CFR 35.6500: General requirements.

(a) Force Account work is the use of the recipient's own employees or equipment for construction, construction-related activities (including architecture and engineering services), or repair or improvement to a facility. When using Force Account work, the recipient must demonstrate that the employees can complete the work as competently as, and more economically than, contractors, or that an emergency necessitates the use of the Force Account.

(b) Where the value of Force Account services exceeds the simplified acquisition threshold, the recipient must receive written authorization for use from the award official.