I didn't file for 2015

lmr7318 — Sat, 01 Jun 2019 04:54:22 GMT

can i file for both 2015 and 2016?

You have to file a separate tax return for each tax year....

jerry2000 — Sat, 01 Jun 2019 04:54:23 GMT

You have to file a separate tax return for each tax year.
Turbotax Online works only for current year (2016) taxes, and not for any other year.
If you want to use TurboTax for any other year you will need to purchase the Desktop Version for each year that you need to file. You can do that at this link:
http://shop.turbotax.intuit.com/personal-taxes/past-years-products.jsp

You can download the Forms and Instructions free from the IRS web site at this link:
http://www.irs.gov/app/picklist/list/priorFormPublication.html

In any event, you have to file the return by mail. Turbotax does not support e-file of prior year returns. Tip: If you prepare multiple years of prior returns, mail each one to the IRS in a separate envelope to be sure that each one is recognized as a separate tax return.

topic I didn't file for 2015 in Get your taxes done using TurboTax

I didn't file for 2015

You have to file a separate tax return for each tax year....