Many people who are nearing the point in their life when they feel it's a good idea to retire may actually need to do some homework on what options they will need to choose when picking a Medicare supplement insurance plan. Although it might seem like homework is something that was left behind years ago when a person was in school, the reality is that the insurance plans chosen right before a retirement phase of lie begins are especially important and require a lot of consideration. Although supplemental plans can indeed be changed at any time, changing a Medicare plan can only happen once a year.