Federal milk orders (FMO) establish minimum class prices that regulated handlers (milk processors) pay for raw milk. See Milk Prices. The sellers of raw milk, dairy farmers (producers) or their cooperative representatives, can bargain with regulated handlers to sell milk at prices higher than the FMO minimums. These higher than minimum prices are called over-order prices and the difference between the prices are called over-order charges or over-order payments. Sometimes the over-order price is referred to as the effective price.

Dairy Programs, via the administration of the FMO program, collects and publishes over-order price information data series – Announced Cooperative Class I Prices, the Over-Order Price Report, and Mailbox Prices. Each of these is described below.