I am going to guess that the reason you are asking this question is due to the retirement of the two coaches on the Colts. The Pats were one of nine teams to opt out of the league-wide pension plan, but the Colts did not. That means that for now the Pats coaches will not be in a similar situation as the Colts coaches were, as the Colts did not opt out of the plan. In addition, I do not believe the Pats have any coaches on their staff that are at retirement age like Tom Moore and Howard Mudd were.
As far as what kind of pension or retirement plan Robert Kraft has put together for the coaches to replace the old plan, that I have no idea. Typically that type of thing is not publicly announced, but I would guess that the Patriots new plan will be good enough that it will keep the current coaches happy and will not deter any coaches from joining the Pats in the future.