Yes, you can file taxes for 2016 before you amend taxes for 2015. You can follow the steps below to amend your return.
To File an Amended Return:
1. Wait for your return to be accepted or rejected by the IRS
2. Log into your account, and at your tax timeline select your "2015
Tax Year"
3. Select to "Amend (Change) 2015 return" and
follow the directions
https://ttlc.intuit.com/replies/3288565
