Deductions & credits

Thank you for the quick reply.   

Here's a silly question; how is taking a big distribution from my IRA any different than if I suddenly got a job paying more mid year?  In such a case Obamacare subsidies only adjusts for the months that I would have earned more, leaving the subsidy in place for other months.   If I "received" my lump sum from my IRA in one month, how is this different than my example?