Who are the knaves in charge who did not elect to defer before the effective date, or elected a disproportionately smaller amount, and will go all-in after? And who are the chumps who overweighted early?
But don't forget - once they go over 120, they would need to get down below 100 to use the SF again!
If between 80 and 120, get to continue using same form as year before. Unlikely that sponsors would really want to continue using 5500 if fell below 100 and otherwise qualified for the 5500-SF. But could if they wanted to if stayed over 80.
Medicare Part C is also known as Medicare Advantage Plan.
Medicare premiums are not reimbursable because Medicare is not a group health plan and if integrated with another employer group health plan raises the " Medicare secondary payer" problem which is noted in Notice 2015-17 Answer 3.
Also while "Medicare secondary payer" might only apply to employers with less than 20 employees, Notice 2013-54 and the EPP prohibition applies to employers with more than 2 employees, and state laws might also be applicable.