Do I click on the box for cost basis not reported if I downloaded my 1099 B from Robinhood investing app? I am unsure if I should check the box for all transactions or leave it blank.

[DavidS127]

It depends.  The downloaded 1099-B may already have selected the correct boxes in TurboTax and appropriately left others blank.

If not, I've copied below the descriptions of the categories of transactions reported on the 1099-B, from the IRS Instructions for 1099-B at this link.  I've highlighted the codes related to "cost basis not reported" to help you correlate your transactions with the correct code.

Applicable Checkbox on Form 8949

Use this box to enter a one-letter code that will assist the recipient in reporting the transaction on Form 8949 and/or Schedule D (Form 1040 or 1040-SR). Use the code below that applies to how the recipient will report the transaction.

Code A.

This code indicates a short-term transaction for which the cost or other basis is being reported to the IRS. Use this code to report a transaction that the recipient will report on Schedule D (Form 1040 or 1040-SR), line 1a, or on Form 8949 with box A checked with totals being carried to Schedule D (Form 1040 or 1040-SR), line 1b.

Code B.

This code indicates a short-term transaction for which the cost or other basis is not being reported to the IRS. Use this code to report a transaction that the recipient will report on Form 8949 with box B checked with totals being carried to Schedule D (Form 1040 or 1040-SR), line 2.

Code D.

This code indicates a long-term transaction for which the cost or other basis is being reported to the IRS. Use this code to report a transaction that the recipient will report on Schedule D (Form 1040 or 1040-SR), line 8a, or on Form 8949 with box D checked with totals being carried to Schedule D (Form 1040 or 1040-SR), line 8b.

Code E.

This code indicates a long-term transaction for which the cost or other basis is not being reported to the IRS. Use this code to report a transaction that the recipient will report on Form 8949 with box E checked with totals being carried to Schedule D (Form 1040 or 1040-SR), line 9.

Code X.

Use this code to report a transaction if you cannot determine whether the recipient should check box B or box E on Form 8949 because the holding period is unknown.