<prompt> Human: A majority of people here are probably expecting a refund on their 2015 taxes, so it can be tempting to file a return as soon as that W-2 rolls in. However, you should also be wary of unexpected tax forms that can come in pretty late into tax season, which could mean you have to waste time and maybe money later filing an amended return. Examples include 1099-INTs from forgotten accounts, various health insurance-related forms 1098-SA, 5498-SA, 1095, adjusting cost basis for ESPP sales form 3922 etc. A lot of these arent required for filing your taxes, but might contain information that could mean having to alter some simple fields or a single checkbox.Even if youre absolutely sure you have everything, your employer, bank, brokerage etc. could send out a corrected form in case they discover a calculation error after the fact. It is best to wait an additional month or so and be absolutely sure that youre filing with the correct up-to-date information.  <response>: All you have to do to see evidence of this is to hang out in this sub for a little bit. There have been a ton of I didnt know this tax form was coming what do I do I already filed posts. 