do I need to amend my tax return if I got a late 1099-K. I have already filed my taxes. The amount was already included in my tax return under "Other Income"?

It depends on what you received the 1099-K for.  

 

If the 1099-K was for something that should have been entered as self-employment income then it should have generated a schedule C and been subject to additional taxes.  TurboTax has a great article here to help determine if you earned income from self employment.

 

However, if the 1099-K was sent to you to report the sale of personal items or something along those lines then you reported it properly and you don't have anything to change on your return so no need to amend it.

 

@waynemarcum