if you used Turbotax online the 2016 return should be there. many taxpayers have multiple accounts.
see this link for account recovery
https://ttlc.intuit.com/turbotax-support/en-us/help-article/security-risk/account-recovery-request-t...
@tagteam is correct if account recovery fails. you get a transcript
but if for some reason you need a copy of that return there is a form and a fee of $43
https://www.irs.gov/pub/irs-pdf/f4506.pdf
