Form 1099-C shows debt you had canceled, forgiven or discharged for less than the amount you owed during the tax year. The amount you didn’t have to pay is generally considered taxable, however, there are exceptions.
Go to this section in Credit Karma Tax: Cancellation of Debt - Form 1099-C
Credit Karma Tax will help you determine if some or all of your canceled debt is taxable based on the information you provide.
You can also learn more about Canceled Debt – Is It Taxable or Not? from the IRS.