It is assumed by many that you only have 90 days to object to a personal tax assessment. It is not as well known that you actually have until the later of 90 days and one year from the original filing due date. Your 2015 personal tax return was most likely due on April 30, 2016. As such, you can still object to it until April 30, 2017.
You can even object to 2015 if it was assessed in full accordance with your 2015 tax return. Contact Jeff Glasner to discuss.