Oops, I looked at the wrong numbers.  Sorry about that.

He is actually at 421% (Form 8962 shows 401% for anything over 400%).

So 400% is $49,960.  As Lisa pointed out, if the taxpayer can contribute $2631 to a Traditional IRA, that would lower his MAGI down to 400% (due to rounding, the taxpayer can probably contribute less than that).  That will qualify him for the Premium Tax Credit.  That is a great way for him to save a lot of money.