How long do I have to make corrections after a report is rejected from the IRS?

For a "Rejected" filing, you have 60 days from the date of the rejection. 

The IRS will only give us 60 days from the time of the original submittal to fix these rejections. If these are not fixed within this time frame, the IRS will not allow us to amend the filing later, and this filing will not count as a good faith effort.

For filings that are 'Accepted with Errors' the IRS has simply advised that you submit your corrections as soon as possible. Only filings that reach the 'Accepted' or 'Accepted with Errors' status are counted as a good faith effort.