The Cooperative Purchasing program began in the early 1980s as a way to benefit member municipalities. Its objectives are to use the collective buying power of a group of municipalities to achieve reduced prices for commodities and services municipalities must buy and to save municipalities the cost of having to prepare their own bids.

SMRPC offers fuel oil, road striping and paper bids at no cost to member municipalities. Additional bids such as road salt, police cars, road signs, tires and tubes and road paving are offered through Greater Portland Council of Governments (GPCOG). They charge an administrative fee (based on percentage of purchase) to SMRPC towns that purchase through their bids.