<prompt> Human: I recently filed my 2015 tax return. It was approved and I received my refund. The problem is Ive had an extremely strange working year in which I held 3 jobs. I had forgotten I officially started the 2nd Job I held in Jan of 2015 and not 2014 and technically on paper was paid in Jan 2015 by the first. I also moved apartments so I never received the first companys w-2 until last night when they tracked me down. As it currently stands I have filed two w-2 for roughly an income of 140,000 for last year. I was already paying the max in social security with what is currently filed as well as federal. The amount of the un-filed w-2 is 11663 taking me to 150K and within the same tax bracket the withholdings were very large 2088 fed, 723.14 social, Medicare 169.12. I know to not fuck with the IRS but in this situation it just seems like the government would owe me more money. Filing an amended return can take several months and is obviously a pain in the ass. What sort of risk am I at just letting things stand as is. IE: is there some massive penalty that they could levy on me a year from now or would it just be you need to file that return and deal with the bullshit then. The extra 500 I could get just doesnt seem worth it for the level of work. I just want to understand if I could be fined by some insane amount even though I have obviously over paid on taxes last year. Appreciate any insights you guys may have.  <response>: Filing an amended return does not take months. In your case Im guessing it would take less than an hour. Processing by the IRS will take a month or two after you mail it in.Lets put it this way. If you owe the IRS then the level of penalties and interest on the underpayment will seriously increase after April 15th. If the IRS owes you money then there will be no penalties but do you really want to walk away from that cash to avoid an hour or less of paperwork? 