JOEL - I am sure the amount of time one would need to wait depends a lot on the circumstances of the disfellowshipment and on whatever personal revelation your Bishop receives on the matter.
According to LDS Church policy, a person who is disfellowshipped may not hold a temple recommend, serve in a Church leadership position, or exercise the priesthood in any way for at least one year. He can attend meetings but not participate actively in them.
I can find no guidelines that specify 5 years waiting time, although it may be one of those "unwritten" recommendations that Bishops are given for most disfellowship circumstances. However, after at least a year, when a member shows true repentance and satisfies any conditions imposed for repentance, the presiding officer may convene a disciplinary council to consider restoring him to full fellowship. I would assume "full fellowship" would include the possibility of being placed in a leadership position if and when the Bishop feels it is appropriate.