Did you use desktop download software or did you use online TurboTax? If you used desktop software the return are stored only on your own hard drive or any back up device you used like a flash drive.
hhttps://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-return/find-last-year-tax-data-file-tax-file-computer/L0XJvPaJr_US_en_US?uid=m6gufxei
https://ttlc.intuit.com/turbotax-support/en-us/help-article/data-systems/find-tax-data-file-mac/L4VN...
If you used online TurboTax, each return needs its own account and user ID. If you use the same account and same user ID for two returns, the second one overwrites the first one and the first one is lost forever.
Check to see if you just forgot how to access the accounts.
Many people have multiple TT accounts and forget how to access them. Log out of the account you are in now.
https://ttlc.intuit.com/turbotax-support/en-us/help-article/account-management/many-intuit-accounts-...
Account Recovery
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
