I know every agent has run into this a ton over the yrs . You get a call from a referral who just retired and got his part B . It's July 5th and his part B became effective 7-1 or even 6-1(ss backdated). You can't write him using icep . Yes you can use retro sep but it's pia . Starting in 2025 this example has under 9-1 to sign up . They now give 2 addition months after the effective date .