What it is:
Box 33a is used to indicate the HIPAA National Provider Identifier number. Enter the NPI number of the billing provider in 33a.
Therabill will the information from the NPI box on the Edit member information dialog to populate box 33a.
Click on Admin->Member Info to bring up the Member (Billing Provider) Information page. Click on the green Edit button to bring up the Edit member information dialog. Enter the billing NPI in the NPI box and select the type of NPI from Individual or Organization.
You can over-ride the NPI that goes out in Box 33a by using Billing Provider Information only to a Specific Payer.