The form CMS-18-F5 (Application for Hospital Insurance, OS 15060.085) is the preferred application for Premium-HI. However, as with SMI, any signed statement requesting enrollment that is filed with SSA/CMS during an enrollment period constitutes an effective enrollment. If an individual filing for Premium-HI does not have SMI, one must also complete the SMI enrollment portion of the application or submit a written request for SMI enrollment at the same time.