Final answer:
The earliest Joey can sign up for his MAPD is the month his Part B coverage begins, and he has up to eight months after this start date to enroll. His MAPD coverage must begin no later than the month after he enrolls.
Step-by-step explanation:
The earliest and the latest day possible for Joey to sign up for his Medicare Advantage Prescription Drug (MAPD) plan is based on a special enrollment period called the Special Enrollment Period for Part B. Since Joey retired and lost his coverage at the end of October, his Special Enrollment Period would begin when he first becomes eligible for Part B and lasts for eight months. As Joey enrolled in Part B with coverage starting on June 1st, the earliest day he can sign up for an MAPD plan is the start month of his Part B coverage. The last day for him to sign up would be eight months from June 1st. Joey's MAPD coverage must start no later than the month after he signs up for the plan during this period.