The National Animal Health Monitoring System (NAHMS) is sponsored by the USDA:APHIS:Veterinary Services (VS). The NAHMS Layers '99 Study was designed to provide information about the nation's layer population for education and research purposes. The USDA's National Agricultural Statistics Service (NASS) collaborated with VS to select a statistically-valid sample from 15 states for Layers '99. The 15-state target population accounted for over three-quarters of the table egg layers in the U.S. as of December 1, 1998. The study was limited to companies with 30,000 or more layers. While the majority of farm sites were contract farms (61.0 percent), the majority of birds were located on company owned farms (72.6 percent), indicating that company owned farms tended to be larger than contract farms. The Central region had the largest percentage (23.0 percent) of farm sites with 200,000 or more layers and also the largest percentage (40.5 percent) of farm sites with fewer than 50,000 layers. The vast majority of flocks (95.6 percent) and layers ( 98.8 percent) were white egg layers. (The New England states, which have a higher percentage of brown egg layers, were not involved in this study.) Almost two-thirds (61.8 percent) of farms sites obtained all of their most recently placed pullets from a single pullet raising site, while 13.6 percent of farm sites assembled their most recently placed flock from four or more different farm sites. The majority of farm sites (71.3 percent) obtained all their replacement pullets from primarily cage reared facilities, although the majority of the farm sights in the Southeast region obtained pullets from primarily floor reared facilities. Layers on 69.6 percent of farm sites came from pullet facilities that monitored for Salmonella enteritidis (S.e.) Ten percent of farm sites obtained replacement pullets from facilities that used competitive exclusion product in pullets to reduce S.e. Overall, 89.0 percent of farm sites obtained pullets that had been vaccinated against fowl pox. On average, 3.7 pounds of feed were needed to produce one dozen eggs. About two-thirds (67.1 percent) of farm sites fed between 3.0 and 3.9 pounds of feed per dozen eggs produced. Contact for this paper: Lindsey Garber.