In the January 2001 Physical Medicine & Rehab Coding Alert, the reader question Billing PT Services Incident To on page 7 stated that billing therapists claims under the therapists own identification numbers is a good idea instead of billing them incident to. Although HCFA has not specifically stated how therapists should bill when employed by physician practices, Medicare (and Stark II, the governments anti-kickback law) rules suggest that therapists employed by physicians should bill incident to, using the physicians provider numbers, and the incident to billing rules would apply. If the therapist has a Medicare provider number and considers himself or herself in private practice (as a consultant to the physician practice), the therapist can provide services to the practice using his or her own provider number as long as the state allows therapists to form private practices and the physician does not benefit financially from the therapists services. Therapists and medical doctors should not enter into any contracts that involve incentives based on number of referrals, etc., to avoid violating any Stark II laws. Always check your state licensing and Medicare carrier guidelines before billing for this complex issue.