My wife has federal student loans. She has been in a IBR for several years. We have always, filed joint. We are, for the first time, being told we have to file married but separate. We went from getting a $1100 return to me owing $4000!

We are in trouble. If she doesn't do the IBR her payment goes from $35/month to $700!!!

We had a prenup keeping our previous debts separate and that had worked for the last 4 years. Not sure what to do! Help!