| Yes, I do suggest that you immediately file an amended tax return before the IRS discovers the error and assesses interest and possible penalties. Usually, an amended tax return does take anywhere from 4 to 6 weeks to process, but if you owe additional taxes these checks would be immediately cashed by the IRS.
I suggest that you do not worry about the time to process the amended tax return, rather you should take the initiative to file the amended tax return as soon as possible. | 
