...a recipient of the Kennedy Center Award must be alive and willing to go to the ceremony.
Several friends who worked on the ceremony have reported that a surprising number of folks turn down the award including some named here as deserving but not honored before their deaths. Each have their reasons, I am sure. Doris Day is the person with the most clear record of refusing, but there are apparently many others.
The only person mentioned who has gone on record as being willing to accept but never having been asked is the Divine Miss M, although her reference to this is from some time ago and was mostly a cheeky comment.