I'm $400 short of my $1100 medicare safety net threshold. I'm probably going to end up paying a $2000 obstetrician fee before the end of the year. Do I keep it back until 2012 before I submit it or should I submit it before the end of the year? Will it make any difference to how much I get back? I don't really understand the threshold thingy but obviously I want to get as much back as I can from the $2000. Can anyone help shed some light on this please?