Market-ready inventories are cattle which have reached an adequate degree of feeding finish but which have not been sold. The level of market-ready inventories appear to have an important impact on fed cattle prices, are discussed in industry and outlook publications, but have not been used in fed cattle price models. This work finds that incorporating measures of market-ready inventories into autoregressive models of monthly fed cattle prices will improve explanatory power but not the forecast performance of these models. Public data are insufficient for forecasting over this time horizon.