<prompt> Human: I efiled my taxes in late February early March.Immediately after doing that however, I realized I forgot to add a Schedule K which cost me 150.I went through the process on TurboTax to file the amended return and never got around to mailing it in.Is it too late to file the amended return?  <response>: Generally, you must file Form 1040X within three years from the date you filed your original tax return or within two years of the date you paid the tax, whichever is later. Be sure to enter the year of the return you are amending at the top of Form 1040X. 