TubroTax states that I have an $18,000 Capital Loss that was not ported to my CA 540 because CA doesn't use that amount. How do I use the CA forms to figure this out?

Assuming you are referring to a capital loss carryover from your 2022 California tax return that you are trying to enter into your 2023 tax return, you will need to follow these steps.  

The California capital loss carryover from 2022 will be reflect on your 2022 California Capital Loss Carryover Worksheet.  The amount on line 8 is your capital loss carryover amount for 2023.  You will need access to your 2022 California state return to find this worksheet and determine the correct amount to enter into TurboTax for your 2023 tax return.

Once you find this amount using the steps above, you will be able to enter it your 2023 tax return as follows.

If you are using TurboTax online, once you locate the amount, you can log back into TurboTax and select Your State Returns from the panel on the left.

1. Select Edit to the right of your state.
2. Select edit to the right of Income and adjustments
3. Proceed through the screens until you see the screen titled "Here's the income that California handles differently."  
4. Scroll down to the section titled Investments and select start/revisit to the right of Capital Loss Carryover from Last Year.
5. You will be prompted to enter your state specific capital loss carryover amounts from 2022.

If you are using the desktop version of TurboTax, you can enter the California capital loss carryover amount in the state interview section of the program.

1. Select the State Taxes tab and then select edit to the right of Income and adjustments.
2. On the page titled "Here's the income that California handles differently, select edit to the right of Capital Loss Carryover from last year.  
3. You will be prompted to enter your state specific capital loss carryover amounts from 2022.