Here is what you have to do in the DME system: 
1. IN the clam the DME type needs to be C

2. Type of Service needs to be O (OH) for oral.
The Type of Service (TOS) field can be found on the claim line (CONT) entry screen,

3. The NDC# has to be in the item file.  Enter it in the NDC #:
 box on the General tab; the NDC number must not contain
any spaces or dashes or other puncutation.  NDC MUST BE IN
542 FORMAT EXAMPLE 12345123412

4. The number of units cannot exceed three digits

5. Days supply is required (this field can be found on the claim line (CONT) entry screen, )

6. the first 4 lines are reserved for items that have NDC#'S the last two lines are reserved for items that have procedure codes.  so if you have a claim with an ndc# it goes in line one and if there is a fee that uses
a hcpcs procedure code then it goes into line 5 or 6

After making these fixes the claim may be resubmitted.