That's okay. Just print out the 2015 tax return and send it in. You will not be able to e-file 2015 return. I would go ahead and mail the 2016 tax return as well. This way the IRS gets both tax returns at the same time. However, they will be processed individually.
If you owe taxes from the 2015, you will also like owe penalties and interest for not filing and not paying. However, if you can show the IRS that this was not done in an effort to skip out on your responsibility to pay tour fair share of taxes, they will generally abate the penalties. They will not waive the interest though. That being said, it may be a good idea to talk to a local CPA about communicating to the IRS on your behalf.
If you are due a refund from 2015, you are still within the time limit to get that refund sent to you. However,
time matters with tax refunds because the law gives taxpayers who fail to file
their income taxes three years to submit a return and claim a refund. The
three-year countdown starts on the original due date.
