Annoyingly, such changes are often not implemented until an update release sometime in December, despite the updated limit having been announced by the IRS more than a year earlier. Until the limit is corrected in TurboTax, you can use overrides in forms mode on the Keogh, SEP and SIMPLE Contribution Worksheet. You'll need to override Part III line 8 to have $54,000, then override Part V lines 1 and 2 to apply the result calculated on Part III line 21, if different.
Be aware that if you override the lines in Part V, you'll need to manually update those amounts each time you make a change to your SE profit that results in a change to the amount calculated on Part III. You'll also need to removing the override in Part III each time you update TurboTax, checking to see if the limit has been corrected.
