To put the study's definition of "extremely rare" in perspective: the FAA's operational error rate (i.e., allowing two planes to be too close together) is 31% better (1 in 149,074 operations).
Effective immediately, Medicare does not cover these events, which apply to hospitals, doctors and "any other health care providers and suppliers involved in the erroneous surgeries. " This is a change in coverage limitations from some other 'never events', which had applied to hospitals only.
CMS, in an apparent moment of dark humor, stated that "instructions for processing such claims will occur at a later date." Yet CMS is quite serious about this, as only 11 states prohibit wrong-site billing.
Stories involving wrong site procedures regularly make the news such as this three time occurrence of wrong site brain surgery in Rhode Island (link on the picture):
Clarke J, Johnston J and Finley E. Getting Surgery Right. Annals of Surgery. 2007;246:395-405.
Kwaan M, Studdert D, Zinner M and Gawande A. Incidence, Patterns and Prevention of Wrong-Site Surgery. Archives of Surgery. 2006;141:353-358.