Did you fill out the Qualified Dividends and Capital Gain Tax Worksheet?
I tried - it was confusing so I am not sure I did it correctly. The other worksheets cited don’t apply.
Is that worksheet where I would somehow get the number for 15% tax.
I do have a few hundred in STCG. I don’t understand why the forms have you add STCG and LTCG.
Do you have a source for a really simple example to use as a guide?
It is confusing and complicated.
On the Qualified Dividends and Capital Gains worksheet, you basically figure your taxes two ways. One way is assuming all of your taxable income is taxed at ordinary rates. The second way is calculating capital gains rates on the portion of your taxable income that is preferenced. At the very bottom of the worksheet, you compare both methods and get to use the one that is better.
The amount of your income that is taxed at 15% should be the number on line 17 of that worksheet, and the actual tax (15% of that number) ends up on line 18. This ends up getting added in with your ordinary income taxes on your ordinary income (line 22), and any income taxed in the 20% capital gains bracket if you have that high of an income (line 21).
If you've done it right, the total on line 23 will be lower than the number on line 24, and the number from 23 will carry down to line 25 and be copied onto the "tax" line of your 1040.
Where are you seeing STCG and LTCG added together? I'm guessing it's probably on Schedule D, and that probably has to do with the fact that ST and LT stuff is lumped together (i.e., they offset each other) before being fed into other parts of the tax process. That's normal, and expected, and how the tax law works.