My withholding shows an amount that ties to my W-2. It also shows an amount called "other withholding". I can not find a document that has any other withholding.

It is hard to say where the additional withholding is coming from, with some context as to where in the program you are seeing it.  Based on the limited information it sounds like it be from you entries for withholding by quarter.  Where are you entering your withholding by quarter?  Where are you seeing "additional withholding"?

If you have high wages or earned income there is an extra Medicare tax on Schedule 2 line 11 which goes to 1040 line 23. That is offset with an extra amount of withholding on 1040 line 25c.