Question: Can we report a nurse practitioner’s (NP) services to Medicare with a locum tenens modifier? He is filling in for one of our NPs who is on vacation. Codify Subscriber Answer: No, you cannot report modifier Q6 (Service furnished under a fee-for-time compensation arrangement by a substitute physician; or by a substitute physical therapist furnishing outpatient physical therapy services in a health professional shortage area, a medically underserved area, or a rural area) to Medicare for an NP’s service. Here’s why: Modifier Q6 was originally designed to represent locum tenens (or substitute) services of one physician for another, but the modifier does not apply to nurse practitioners. “Services of non-physician practitioners [NPP] (e.g., CRNAs, NPs and PAs) may not be billed under fee-for-time compensation arrangements or reciprocal billing reassignment exceptions. These provisions apply only to physicians,” reminds MAC Noridian Healthcare Solutions in online guidance. Keep these tips in mind when filing claims that do qualify for modifier Q6: PT shortage: There is a physical therapist exception for appending Q6. “With one exception, [a] physical therapist in a health professional shortage area (HPSA), a medically underserved area (MUA), or in a rural area” can append Q6, Noridian mentions. Final note: Modifier Q6 has no effect on payment.