I am not a US citizen and will be leaving the US at the end of this year. If I leave money in a US savings account will I need to file a US tax return for 2021?
Leaving money in the account is not a tax issue ... needing to pay income tax on the earnings is the issue. Depending on the amount it earns you may need to file a 1040NR. TurboTax doesn't support that form ...
OK so seems like I don't have to file a tax return for 2021 as I will be a non-resident alien (I will not be spending any time in the US in 2021) and my only income will be from US banks that is not a trade or business. Does that sound right to you?
If possible before your departure from the U.S., I would suggest you find a tax pro you can establish a repore with before you leave that is familiar with non-resident tax filings. That way, if things change in the future and you are required to file a U.S. non-resident tax return, you have a point of contact. That tax pro can be either in the U.S. or in your home country.
Since TurboTax does not provide or support the 1040-NR for non-residents, you might also want to check out www.sprintax.com which is a website that specializes in 1040-NR non-resident tax returns. They even provide the ability for you to complete the 1040-NR online and e-file it. This website is the one recommended by TurboTax for non-resident tax filers. I personally know a few non-resident foreign exchange students who have used it in the past and give it a thumbs up.
The key is to educate yourself on this "before"you depart the U.S. Trying to learn the ins and outs from your home country can be difficult.