How can I get a copy of an old tax return (2012) that my ex husband filed (we filed jointly that year)? He did the taxes and had the passwords.

[Carl]

Nope.  Since he's your "ex" you have no legal right to access his account. however, you can get a transcript for free from the IRS at <a rel="nofollow" target="_blank" href="http://www.irs.gov/individuals/get-transcript">http://www.irs.gov/individuals/get-transcript</a>. If you need a copy of the actual tax return, the IRS will charge you $50 for each year you need.

[Critter]

Well you could get a copy from him or the userID & password to access the return.         

You can get a return transcript from the IRS for free :  http://www.irs.gov/Individuals/Get-Transcript

For a $50 fee you can get a copy of the return from the IRS:  https://ttlc.intuit.com/questions/1901218-can-i-get-a-copy-of-my-tax-return-from-the-irs