Form 8615, Tax for Certain Children who have Investment Income is expected to be available on 03/06/2020.

But how do I opt to use parents' tax rate rather than the Trust rates? I updated TurboTax yesterday; the update was marked CRITICAL, but I see no way to take advantage of the parents' much lower tax rate, e.g. zero tax on capital gains.

I am pretty sure that the first time I opened the student's tax return on the updated TurboTax, I saw an option to select the alternative tax computation, but I can't find it again.

Thanks for any help you can give.

To use your parent's tax rates, you would need to choose the Pre-TCJA rates on the screen.  

In TurboTax online,

• After sign back into your account, select Pick up where you left off 
• To the right upper corner, in the search box, type in "kiddie tax"
• Select Jump to kiddie tax
• Follow prompts
• On-screen, Election to Use Pre-TCJA Rules, select yes
• See the image below

If this does not work, you may want to delete the Form 8615, then revisit the section.  To delete, here are the steps:

• Sign in to your account, select Pick up where you left off
• To your left, Select Tax Tools/drop-down menu
• Select Tools
• Under Other helpful links, choose to Delete a form
• Select Delete next to Form 8615 and Continue with My Return to proceed

I found that if I switched to the Step-by-Step process (I prefer to work directly on the forms) that as soon as I had entered interest, dividends, w-2s, and 1099-MISC, I was shown that screen about opting for parents' tax rates. But thank you for posting this alternative method.