Patulin is the most common mycotoxin found in apples and apple juices. The objective of this study was to determine the concentrations of patulin in (i) apple cider produced and marketed by Michigan apple cider mills during the fall seasons of 2002 to 2003 and 2003 to 2004 and (ii) apple juice and cider, including shelf-stable products, marketed in retail grocery stores in Michigan throughout 2005 and 2006. End product samples (n=493) obtained from 104 Michigan apple cider mills were analyzed for patulin concentration by using solid-phase extraction followed by high-performance liquid chromatography. Patulin was detected (> or =4 microg/liter) in 18.7% of all cider mill samples, with 11 samples (2.2%) having patulin concentrations of > or =50 microg/liter. A greater percentage of cider samples obtained from mills using thermal pasteurization contained detectable patulin (28.4%) than did those from mills using UV light radiation (13.5%) or no pathogen reduction treatment (17.0%). Among retail grocery store samples (n=159), 23% of apple juice and cider samples contained detectable patulin, with 18 samples (11.3%) having patulin concentrations of > or =50 microg/liter. The U.S. Food and Drug Administration (FDA) action level for patulin is 50 microg/kg. Some apple juice samples obtained from retail grocery stores had exceptionally high patulin concentrations, ranging up to 2700 microg/liter. Collectively, these results indicate that most apple cider and juice test samples from Michigan were below the FDA action level for patulin but that certain apple cider and juice processors have inadequate controls over patulin concentrations in final products. The industry, overall, should focus on improved quality of fruit used in juice production and improve culling procedures to reduce patulin concentrations.