Sometimes a surgeon performs a major surgery (like a hip replacement), but the patient returns to their hometown the next day, and a local primary care doctor or different orthopedist handles all the 90-day post-operative care. This requires "split billing" using Modifier 54.
How Modifier 54 Works
Modifier 54 (Surgical Care Only) tells the payer: "I performed the surgery, but I am relinquishing the post-operative care."
The surgeon bills the CPT code with Modifier 54. Medicare will pay them roughly 70-80% of the total global fee (covering the pre-op and intra-operative work).
The Post-Op Doctor (Modifier 55)
The local doctor who assumes the post-operative care will bill the exact same surgical CPT code, but append Modifier 55 (Postoperative Management Only). They will receive the remaining 10-20% of the global fee for managing the patient for the 90 days.
Transfer of Care Documentation
A formal, written transfer of care agreement must be signed by both physicians and kept in the patient's medical record to legally justify splitting the global fee.