Can you explain "basis adjustment"?

Yes, for various reasons you broker may not know, or may have posted an incorrect cost basis.  

• The most common is that they post a Zero (0) as the cost basis.
• Since the IRS gets the 1099-B from the broker, you should always post the form exactly as it is.
• But a Zero for a basis will result in the taxing of the entire amount of the sale.
• Therefore, you must do a "Basis Adjustment".

1. Start at Federal
2. Wages and Income
3. Scroll to Investments & Savings
4. Select Stocks, Cryptocurrency, Mutual Funds, Bonds, Other (1099-B) [Start or Revisit]
5. If you already have an entry, select the appropriate broker or add another account.
6. Select your broker or follow the interview.
7. As you enter the dates and proceeds, there is a check box for The cost basis is incorrect or missing on my 1099‑B
8. Use this option to correct any errors on a cost basis.