Medicare supplements can be changed during the year at any time. There is not a certain time period designated for changing to another Medicare supplement, although you may be subject to underwriting and not guaranteed issue. If you have received a rate increase during the year or would like to shop around to see if you can get a different plan or less expensive plan you are always free to do so. Be aware that insurance companies can underwrite. You will probably be asked to complete an application including health questions, but for many people this is not difficult. Even if you had a heart attack 5 years ago or had internal cancer 3 years ago, getting a new policy would generally not be a problem.