Almost four months after the new Medicare definition of “substantive portion” for split/shared visits took effect, physicians and nonphysician practitioners (NPPs) are hanging their documentation hat on a few words in the 2024 Medicare Physician Fee Schedule (MPFS) rule, which adopted the CPT editorial panel’s definition of substantive portion.^[1] The rule states only that the physician or NPP who performs and bills for the split/shared service is expected to document medical decision making (MDM) unless they base the substantive portion on time. CMS has not been any more explicit in the Medicare Claims Processing Manual, and guidance from some Medicare administrative contractors (MACs) on split/shared billing appears to be inconsistent, an expert said.

“This could still be a win, but there’s confusion around documentation,” said Cathy Archuleta, a senior manager with SunStone Consulting. “I don’t think they necessarily gave a lot of consideration to how the CPT definition, which is pretty nuanced, impacts documentation.”

Medicare pays for an evaluation and management (E/M) service provided in part by a physician and in part by an NPP at an institution (e.g., hospital, skilled nursing facility). Split/shared visits are billed under the National Provider Identifier (NPI) of the physician or NPP who provides the substantive portion of the visit—with a 15% drop in reimbursement if the visit is billed under the NPI of the NPP. The 2022 MPFS rule had phased out history, exam and MDM as a basis for determining the substantive portion, leaving time as the only option starting in 2023; however, CMS delayed implementation, and in the 2024 rule substituted CPT’s definition for its own.