This is a partial article from the Therabill Fee Schedule knowledge base article.
Different Fee's for a Service Code Modifier
If you want to charge a different fee when a service code modifier is used then you will need to do a Modifier Split on the service code in the fee schedule. Before we go in to how to perform a modifier split, we will first give an example of what this means. An example (and probably a bad example) of this might be that you charge $100.00 for service code 90834. However, when you use the 24 modifier, you want to charge $130.00. In order to accomplish this, you need to create a new row in the fee schedule. This row will correspond to the service code with the modifier. To accomplish a modifier split, put your mouse over the row corresponding to the service code that you want to add the modifier to. When you put your mouse over the row, a small modifier split icon will appear at the left of the row. Click on that split icon.
You will now see the form shown to the right. Enter the modifier that you want to add to the CPT code in the text box. In our example, you would enter '24' (without the quotes) in to the text box. Now, click the Add Modifier button to create the row. You will now see a new row in your fee schedule (under the original service code row). This new row will be labeled with the service code + modifier.
DO NOT enter the service code as part of the modifier. For example, do not enter 90834.24 as the modifier. Just enter 24 as the modifier.
What about multiple modifiers
To enter multiple modifiers, separate the modifiers by a period. For example, 'GO.KX' would be the modifier GO and KX.