The median wait time to be treated in the Emergency Department was about 30 minutes, and the median treatment time was slightly more than 90 minutes in 2010–2011. At visits in which patients were triaged, the shortest median wait time was 12 minutes for patients who had an immediate need to be seen. Treatment times were longer for patients who were triaged as immediate, emergent, and urgent compared with those who were triaged as semiurgent or nonurgent.
http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6319a8.htm?s_cid=mm6319a8_e