You are insolvent when your debts are more than the fair market value of your assets.
To determine whether or not you were insolvent at the time your debt was canceled or forgiven, determine the amount of your debts and the fair market value of your assets immediately before the cancellation of your debt. If the amount of your debts is more than the fair market value of your assets, you were insolvent. The amount of insolvency is the amount of your debts minus the fair market value of your assets.
Example: Let's say you had $4,000 of canceled debt, and immediately before the cancellation, your debts totaled $21,000, and the fair market value of your assets was $17,500. Because the amount of your debts is more than the fair market value of your assets, you were insolvent at the time your debt was canceled. The amount of the insolvency was $3,500 ($21,000 - $17,500). You would enter $3,500 for the amount of debt that was canceled while you were insolvent.
You can also use IRS
Publication 4681 to help determine if you were insolvent at the time your debt was canceled.