If you’ve already filed your 2018 federal income tax return and used the worksheet in the instructions to Schedule D to figure the 25% tax rate on unrecaptured depreciation and the 28% tax rate applicable to gain on the sale of collectibles, your taxes may change. And for most affected individuals, the change is for the better (a lower regular tax). This is because the IRS made an error in the worksheet; it did not reflect the correct regular tax rates and brackets. Now the IRS has issued revised instructions (https://www.irs.gov/pub/irs-pdf/i1040sd.pdf), correcting that worksheet (it can be found at the end of the instructions to Schedule D).
What to do: If you completed your return using software or a paid preparer, there won’t be any change in your tax computation. The IRS had already informed software firms of the correction. If you are on extension and have not yet filed your 2018 return, which you plan to prepare by reading the instructions to Schedule D, be sure to use the revised ones containing the date May 15, 2019, on the bottom of page D-1. The IRS has not yet said what should be done for returns submitted before May 16, 2019, that contained errors because of the incorrect worksheet.