
If they do, then you do NOT need to enroll in Original Medicare.
If they don't, then you DO need to enroll.
You have a seven (7) month period to enroll in Original Medicare (to avoid a Late Enrollment Penalty. You can enroll as early as 3 months before your 65th birthday (it will become effective on the first day of your birthday month), the month of your birthday (it will become effective on the first day of the month after your birthday month), or up to 3 months after your birthday month (it will become effective on the first day of the month you choose).
For example, let's say your birthday is April 11th.
If you wait longer than that, you'll get a Late Enrollment Penalty attached to your Part B premium - for the rest of your life!