There are two data series for fluid milk sales that are used in the Federal milk order program; "in Federal milk order marketing area sales" and "estimated total U.S. sales of fluid milk products."

In Federal Milk Order Marketing Area (In– area) sales are dispositions (deliveries) of fluid milk products in consumer-type packages from milk processing (bottling) plants to outlets in Federal milk order marketing areas that sell directly to consumers. These outlets include food stores, convenience stores, warehouse stores/wholesale clubs, non-food stores, schools, and the food service industry. In some cases, the disposition is directly to consumers (home delivery). More recently, deliveries to food warehouses/distribution centers are included. Fluid milk products include whole milk, flavored whole milk, 2% (reduced fat) milk, 1% (lowfat) milk, skim (fat-free) milk, flavored fat-reduced milk, buttermilk, and other miscellaneous fluid milk products. The data are reported monthly and are representative of the consumption of fluid milk products in Federal milk order marketing areas. The data series currently accounts for about 81 percent of total sales in the United States. The source of the Federal milk order data are monthly reports filed by milk processors subject to the provisions of the applicable milk order.

Estimated total U.S. sales of fluid milk products are based on the Federal milk order in-area sales described above and sales of Class I products in California. These two data series together account for about 93 percent of total fluid milk sales in the United States. An estimate of total U.S. fluid milk sales is derived by interpolating the remaining 7 percent of sales from the Federal milk order and California data. Sales of individual fluid milk products are shown. Beginning in 2003, sales of flavored whole and fat-reduced milk products are reported as complete data for 2002 are now reported by California. Previously, sales of flavored products were included either in whole milk or the respective fat-reduced milk product. The California data are collected and published by the Dairy Marketing Branch of the California Department of Food and Agriculture; see http://www.cdfa.ca.gov/dairy.

The Federal milk order in-area sales data series includes monthly and year-to-date sales volumes and percent changes from the same month and year-to-date period in the previous year. The estimated total U.S. sales data series includes monthly sales volumes and percent changes from the same month in the previous year. Some of the data have been adjusted for variation due to calendar composition.