Hint: Doctor's schedule will be the key. On-site requirement: To bill a service incident-to, the physician must be present in the office and be immediately available for assistance, consultation, or patient emergencies,should they arise, though not necessarily seeing the patient. "If the insurer ever audits your charts, they will look at the doctor's schedule on the date of the incident- to service," says Heather Corcoran with CGH Billing in Louisville, Ky. "If he was out of the office and your NPP billed incident-to, your insurer will have a lot of questions for you." Tip: Don't assume that just because the physician is involved in the patient's care, her services can be considered incident-to, says Randall Karpf of East Billing in East Hartford,Conn. The physician needs to initiate the treatment and be involved throughout the service via direct supervision. Stay compliant: As in previous years, the OIG has listed incident-to services as an area of focus for their staff in 2009. The OIG's 2009 Work Plan notes that the Social Security Act provides for incident-to coverage. "However," the document states, "these services may be vulnerable to overutilization or put beneficiaries at risk of receiving services that do not meet professionally recognized standards of care. We will examine the qualifications of nonphysician staff that perform 'incident-to' services and assess whether these qualifications are consistent with professionally recognized standards of care."