Reporting gains and losses not reported on 1099B

[tbloomsburgh]

Have info on 1099B but form says not reported.  How do I report for 8949 not reported items?

[Bsch4477]

Are you referring to 1099-B where it reads basis not reported to IRS?  In that case just input the basis as it appears on the 1099-B. If no amount is in the basis box you have to enter what your basis is. If you don’t know and can’t find out the IRS will assume it is zero.