When can I enroll in or change my Medicare coverage?

Medicare has a handful of enrollment windows, and knowing which one applies to you is what keeps you from missing deadlines or paying penalties. When you first turn 65, your Initial Enrollment Period gives you a seven-month window around your birthday to sign up. If you miss it, the General Enrollment Period from January 1 to March 31 lets you enroll, with coverage starting the month after you sign up. Each fall, the Annual Enrollment Period from October 15 to December 7 is your chance to join, switch, or drop a Medicare Advantage or Part D plan, with changes taking effect January 1. If you're already in a Medicare Advantage plan, the Medicare Advantage Open Enrollment Period from January 1 to March 31 lets you switch to another Advantage plan or move back to Original Medicare once. On top of all that, Special Enrollment Periods are triggered by life events like moving, losing employer coverage, or qualifying for Extra Help, and they let you make changes outside the standard windows. This matters because enrolling late in Part B or Part D without other creditable coverage can add permanent penalties to your premiums, and outside of a window that applies to you, your options to change plans are limited. Dates can shift slightly and the rules around Special Enrollment Periods get detailed, so confirm specifics at Medicare.gov or with your local SHIP. A licensed agent can also tell you which window fits your situation, at no cost to you.

— Matt Rolph, Los Angeles, CAVerified