I have a 1099-OID that is divided into two sections: Taxable Obligations and Tax-Exempt Obligations. Some boxes can be found in just one section or the other, but a few, including box 6--Acquisition Premium, appear in both. The TT worksheet corresponding to this form combines the box 6 values for the two parts of the statement. Is this appropriate? Thanks!
so the 1099-OID is already presented split up and you have different boxes on them but Box 6 on both, with different values in Box 6 presumably. If Box 6 has values then you shouldn't recombine them in TT as one 1099-OID - input them separately as two 1099-OIDs in TT and just fill in the boxes provided for each one.
In general if you have premium or accrued interest adjustments on 1099s which have multiple types of income (taxable, treasury, tax exempt etc) then TT won't know how to apply it. You need to split the 1099 by type to get the correct allocation. Adjustments for individual muni bonds across state taxable and state exempt bonds can also be problematic and need to be separated for state tax.
Here's a similar post on 1099-INT but same principles apply to 1099-OID, with good explanation from @SteamTrain