How do I submit a bid or proposal? All formal bids and proposals shall be submitted as specified in the solicitation document.Below are links to solicitations available through Maricopa County. Welcome to the City of Maricopa, AZ, Bid Postings. The bid or Request for Proposal will be designed to be competitively bid following all MCCCD Purchasing guidelines and allowing maximum competition. Instructions to Bidder. Maricopa County's Open and Closed Solicitations are posted below. Please register or login to see details of all open opportunities. The bidder must be registered and provide proof of registration in the federal System for Award Management (SAM) registry at the time of bid submittal. Bid Bond: Submit a certified or cashier's check or a surety bond, payable to Northern.