Site-of-service differential

Medicare uses separate payment systems to reimburse the professional (physician) and facility components of a service. When a procedure is performed in a physician's office, the physician's fee schedule payment includes a higher non-facility practice expense (PE) relative value unit (RVU) to offset overhead costs such as staff, equipment, and supplies that the practice absorbs directly. When the identical procedure is performed in an HOPD or ASC, the facility bills Medicare separately under the Outpatient Prospective Payment System (OPPS) or ASC payment system, so the physician's fee schedule payment uses a lower facility PE RVU—reflecting that overhead is now the facility's responsibility.

The result is a three-way payment landscape for the same CPT code: the physician collects the highest all-in reimbursement in the office setting (no separate facility fee, but higher PE RVUs), a split payment in the HOPD (physician's reduced fee plus a facility's OPPS payment), and a split payment in the ASC (physician's reduced fee plus an ASC facility payment). Because HOPDs often receive higher OPPS rates than ASCs—and because hospital-owned outpatient departments can bill under HOPD rates even for off-campus locations—the cumulative Medicare outlay and patient cost-sharing can vary substantially by setting, even though the clinical service is identical.

The American Medical Association's Council on Medical Service has studied this differential extensively and advocates for site-neutral payment policies backed by valid cost data. The AMA's position encourages CMS to align payment methodology across settings, use CPT codes universally as the basis for payment, and ensure that reimbursement reflects actual practice costs rather than the ownership structure of the facility where care is delivered.

For orthopedic practices, the site-of-service differential has direct financial and compliance consequences: performing a procedure in the office rather than a hospital outpatient department may yield a net revenue difference of hundreds of dollars per case once facility fees and patient cost-sharing are factored in, influencing both practice economics and patient out-of-pocket exposure. Reporting the wrong Place of Service (POS) code on a professional claim—for example, submitting POS 11 (Office) when the procedure was actually performed at a POS 22 (HOPD)—triggers an overpayment because the payer applies non-facility PE RVUs to a service that should carry facility RVUs, creating audit and recoupment risk. Conversely, miscoding POS 22 for a true office procedure underpays the physician. CMS and its Medicare Administrative Contractors actively cross-reference POS codes against facility claims, making accurate site-of-service documentation a first-line compliance obligation for every orthopedic coder.