I just filed my taxes today but left out many charitable contributions and professional expenses. Dang!!! What do I do. I owe the IRS $3000.

[KittyM · Accepted solution]

You will need to file an amended return after your return has been processed by the IRS.  (This usually takes 10-21 days.)  Until your return is processed, please do not change anything on your return in the system. (The IRS has been known to change things during processing, if they find an error.)  After your return is processed, you may file your amendment.  To avoid penalties and interest, you should mail your amendment to be postmarked before midnight, April 17, 2018.  

You will need to use a form called 1040-X, which can be prepared for free in TurboTax. You cannot e-file an amended return.  A 1040X has to be mailed, and it takes 2-4 months for the IRS to process an amended return.  

Here are the instructions to Amend My Return