PrognoCIS Assessment has a provision for assigning one or more modifiers to each CPT code. Please note, these are not assigned to HCPCS codes. These codes influence the variance in charges to be considered. Group Master Type CM has a provision to define the modifier codes, along with the applicable percentage.

If the percentage is 0, it is treated as 100%. If a provider is assisting another provider, they will use one of the modifiers in their bill. The rate then applicable/charged will be factored by this percentage. If more than one modifier is used, it will result in a progressive reduction.
For example, CPT code 10560 has a U&C Rate of $1,000.
Modifier 80 has an associated value of 20 percent.
The effective rate for 10560 with Modifier 80 = 20% of $1,000 = $200.

Modifier 51 has an associated value of 50 percent. If both modifiers are used, then: The effective rate for 10560 with Modifiers 80 and 51 = 50% of (20% of $1,000) = 50% of ($200) = $100.

The rate will be a flat dollar amount for some modifier codes like TC Technical Charges and 26 Professional Charges for Interpretation (like reading a CT scan). The list of these modifiers is defined as a comma-separated list in the property:
Billing > fee.fixrate.modifiers
Please note that the program still prompts for a percentage even for these codes, but the calculation does not consider the value entered here.