Form 1099-B field reference
Form 1099-B Box 5: Noncovered security
Form 8949 destination
Usually box B (short-term) or E (long-term)
Reconcile this field with the rest of the transaction before calculating gain or loss. A Form 1099-B label does not override the official basis, holding-period, or adjustment rules.
Before filing
What to check
- Reconstruct basis from your own records.
- Confirm short-term versus long-term treatment.
- Use the Form 8949 category that matches both holding period and IRS basis-reporting status.