Get your taxes done using TurboTax

It is not too different in 2018:

1. Select Federal from the left side menu.
2. Select Wages and Income toward the top left.
3. Scroll down/ expand the list and look for Investment Income.
4. Find Stocks, Mutual Funds, Bonds, Other and click on Start or Update to the right. 
5. On the screen titled,  Did you sell any investments in 2018, answer Yes
6. On the screen titled,  Did you get a 1099-B or brokerage statement for these sales? answer No.
7. On the screen titled,  Choose the type of investment you sold, select Stocks.
8. On the next few screens, fill in your information about the stock. Since this is not a sale, your sale proceeds is $0, assuming you didn't recover any of your investment. Your sale date would be the date that it became clear that the stock was worthless.
9. On the question, Do any special situation apply to this sale?, select Small business stock.
10. Click Continue.
11. On the next screen, What kind of Small Business Stock?, Select Section 1244 stock.
12. Click Continue.
13. On the next screen select all that apply and click Continue.

See the screen below for the choices that must be selected to qualify for the ordinary loss treatment. All of these four conditions must be true to qualify for 1244 treatment.