My wife passed away in 2020 so I inherited her IRA. She had basis in her IRA due to non-deductible contributions. I made withdrawals from that IRA in 2020 and received a 1099-R. I also have my own IRA with basis. I filed married filing joint in 2019 and filed form 8606 for each of us.
How do I handle the transfer of my wife’s basis to me?
TurboTax can't cope with your two IRAs with basis that took distributions.
You would have to generate the second Form 8606 manually and file on paper.
BUT, if you took no money from your own IRA, there is no issue.
If you elect to treat her IRA as your own IRA you won't have this problem next year.