Demand bids submitted by load-serving entities (LSEs) into current US RTO/ISO-managed day-ahead markets (DAMs) are demands for the delivery of power on behalf of retail customers, with or without accompanying price information indicating willingness to pay. If a demand bid submitted by an LSE into a SCUC/SCED optimization for a DAM is cleared, the LSE is obligated to pay for the resulting scheduled delivery of power to its customers. This chapter shows how the base-case swing-contract market can be generalized to allow LSEs to submit reserve bids with accompanying price (valuation) information permitting the measurement of customer benefits. Three cases are considered: reserve bids with time-of-use (TOU) pricing; reserve bids in the form of quantity-price demand schedules; and reserve bids directly expressed in terms of benefit functions.