If a paid tax preparer made a mistake on your tax return the preparer should prepare amended returns to fix the mistakes you say were made. You can only amend a tax return as far back as a 2017 return to receive a refund.
If you did not use TurboTax to prepare your return, it is possible to amend the return using TurboTax but it will really be a pain. It would be better to use the software or service used to file originally. If a paid preparer made a mistake on your tax return, that tax preparer should do the amended return for you at no charge.
In order to use TurboTax to amend your returns, you need to purchase the desktop software for each tax year and re-create the return EXACTLY as it appeared when it was filed with the IRS/states. Every line has to be the same. Then you have to "trick" the software into thinking you filed by saying you will mail the return. (but do not mail it) AFTER that, you use the software to prepare a Form 1040X, which has to be printed, signed and mailed to the IRS. It normally takes the IRS about 3-4 months to process an amended return. Currently it is taking much longer than normal for the IRS to process amended returns.
**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.**
