Consumer demand for pork carrying various claims of alternative production practices is constantly changing and determining the size of these markets is critical for research and development efforts as well as advertising and promotional activities. The pork industry doesn’t want to spend too much in a market when return may be low, but also doesn’t want to under invest in a high growth, fast moving market. The overriding objective of this project is to provide information the pork industry can utilize to define the percentage of pigs raised without antibiotics for a label claim. Several approaches were used to assess market share. Existing literature and public information were collected, reviewed, and a summary provided to establish baseline values on antibiotic use in pork production. U.S. Department of Agriculture, National Animal Health Monitoring System (NAHMS) swine studies and Agricultural Resource Management Surveys (ARMS) for hogs were the focus of the baseline summary. Data from USDA’s Agricultural Marketing Service were then used to examine trends in premiums paid for non-carcass merit characteristics and market information for pork cuts from specialty programs. Limitations in existing literature, public information, and available data are identified and discussed. A targeted survey of individuals within the pork packing industry was then used to obtain expert opinion about the percentage of pigs eligible and pounds of pork marketed with an antibiotics claim. The information and data from a variety of different sources helps corroborate numbers.