The shared services rule is a Medicare rule, which allows a physician and a Non-Physician Practitioner (NPP) to each provide some portion of an Evaluation and Management service, and to bill the service under the physician's NPI.  The level of service is based on the documentation provided by both clinicians.  Billing the service under the physician's provider number means the visit is paid at 100% of the physician fee schedule, rather than at 85% if billed under the NPP's provider number.

There are limits about what services may be billed as shared services. 

In order to bill an E/M service as a shared service, both the MD and the NPP must see the patient, have a meaningful clinical interaction with the patient, and each must document the portion of the E/M service they personally provided.  Unlike the explicit descriptions of this in the Teaching Physician rules section, there are no examples of acceptable documentation in the CMS manual.

Consults:  Neither inpatient nor outpatient consults may be billed as shared services.  The CMS manual states this explicitly: A consultation shall not be performed as a split/shared E/M visit.  (Pub 100-04, Chapter 12, Section 30.6.10 A)

Office and clinic setting:  In order to bill the services as shared services, the visit must meet incident to guidelines.  Review the guidelines for incident to services before billing office or clinic office visits as shared services.  In brief, you may not bill incident to for new problems, new patients or consults. 

Hospital inpatient/outpatient/emergency department setting:  When a physician and an NPP in the same group practice both provide a portion of the E/M service, and both have a face-to-face visit with the patient, and document this, the service may be billed under either of their provider numbers's.  Because  payment is higher under the MD NPI than the NPP, most groups bill under the MD's number.

Here are the examples from the Claims Processing Manual:

1. If the NPP sees a hospital inpatient in the morning and the physician follows with a later face-to-face visit with the patient on the same day, the physician or the NPP may report the service.

2. In an office setting the NPP performs a portion of an E/M encounter and the physician completes the E/M service. If the "incident to" requirements are met, the physician reports the service. If the “incident to” requirements are not met, the service must be reported using the NPP’s UPIN/PIN.