When Renee filed her 2020 tax return, she neglected to report income from the sale of stock. However, the IRS received a 2020 Form 1099-B from her broker reporting information about the transaction. Nine months after filing, Renee received a CP2000 notice from the IRS proposing additional tax. Renee ignored the notice, as well as a later notice of deficiency. In 2022, she received a bill from the IRS showing tax, penalties, and interest. Renee then reviewed her records and determined that her basis in the stock she sold in 2020 was actually much higher than the amount reported by her broker. Since this reduced the amount of income from the sale, she believes the amount assessed by the IRS