Follow the flowchart to know when you can bill incident-to services and bring in 15 percent more money. Correctly billing your non-physician practitioners' (NPP's) "incident-to" services means the difference between 85 and 100 percent reimbursement. But if you bill incident-to haphazardly, you're just waving a red flag at auditors. Use the following flowchart to evaluate your incident-to claims for all the must-have components. More information: For more on billing for incident-to services, see Medical Office Billing & Collections Alert Vol. 10, No. 5.