Can Performance Incentives Be Included on Schedule Task Orders?
Can Schedule Task Orders Be of the “Fixed-Price Incentive” Type as Described in the FAR?

See:

http://blogs.gsa.gov/blogs/servicesordering.nsf/dx/performance-incentives

Search terms:

GSA Multiple Award Schedule MAS FSS Federal Supply Schedules service services task order orders ordering professional services performance incentive fixed commercial FFP FFP w/EPA T&M LH firm fixed price time and materials labor hour award fee