Orthopedic Billing: How to Stop Losing Money on 90-Day Global Periods

Orthopedic surgery generates the highest per-procedure revenue of any office-based surgical specialty. Total joint replacements (CPT 27130 hip, 27447 knee), spinal fusions (22612 single level lumbar), shoulder arthroplasties (23472, 23474), and complex fracture repairs each carry Total RVU values in the 20 to 40 range with 2026 Medicare payment in the global service running $1,200 to over $2,500. Every one of these procedures carries a 90-day global period. The 90-day global bundles all related post-operative care into the procedure payment. Routine post-op visits, wound checks, suture removal, ordering routine post-op imaging: all included. The economic implication: an orthopedic surgeon performing 200 major procedures per year has 200 90-day windows where the discipline of correct global-period billing determines whether substantial post-op revenue is captured or written off.

The 90-day global period for major surgical procedures (status indicator 090 in the CMS Medicare Physician Fee Schedule) bundles the following into the procedure payment. Pre-operative care for the day before and day of surgery for major procedures (the day before only counts when admission is the day before). All routine post-operative visits and care during the 90-day period after the surgery. Routine treatment of complications not requiring return to the operating room. Routine post-op imaging that is part of normal recovery monitoring. Suture removal and dressing changes. The 90-day global does NOT cover: unrelated E/M services for problems unrelated to the surgical condition, unrelated procedures for distinct conditions, planned staged procedures from the original surgical plan, related procedures requiring return to the operating room for complications, services by different physicians not in the surgical group. Each of the not-covered scenarios has a corresponding modifier that flags the service as separately billable.

Modifier 24 is appended to an E/M code performed during another procedure's post-op global period when the E/M is for a problem unrelated to the surgical condition. Example: a patient is two weeks post total knee arthroplasty (90-day global) and presents to the orthopedic office for evaluation of new shoulder pain (unrelated to the knee surgery). The shoulder evaluation E/M is billable separately with modifier 24. Documentation requirements: the E/M note must clearly establish that the problem evaluated is unrelated to the surgical condition. Different diagnosis code is the strongest evidence (M75.41 right shoulder rotator cuff vs M17.11 right knee primary osteoarthritis). The chief complaint and HPI should focus on the unrelated problem. The plan should not address the knee surgery. Common error: billing modifier 24 for a post-op visit that the chart documents as a routine knee follow-up. The audit defense fails because the documentation contradicts the modifier. Practices that document modifier 24 visits as if they will be audited (and they will, periodically) recover the modifier 24 revenue consistently.

Modifier 79 is appended to a procedure code performed during another procedure's post-op global period when the new procedure is unrelated to the original. Example: a patient is six weeks post total hip arthroplasty (right hip, 90-day global) and undergoes a procedure on the left hand for an unrelated condition (carpal tunnel release). The carpal tunnel release is billable with modifier 79. The right hip global period was for the right hip procedure; the left hand procedure is unrelated and starts its own new global period. Documentation requirements: clear establishment that the new procedure is unrelated to the original surgical condition. Different anatomical site, different clinical indication, different diagnosis. Modifier 79 essentially treats the new procedure as if the original surgery had not happened: full payment, new global period.

Modifier 78 is appended when a patient returns to the operating room during the post-op period for a related procedure (typically managing a complication of the original surgery). Example: a patient is one week post total hip arthroplasty and returns to the OR for surgical management of a wound dehiscence at the original surgical site. The return procedure is billable with modifier 78. The payment is reduced (typically the technical component only, not the full procedure) and the global period is not reset. Documentation requirements: establishment that the return to OR was for a related complication, not a planned staged procedure. Modifier 78 is the right choice when the return was unanticipated and addresses a complication; modifier 58 is the right choice when the return was anticipated as part of the original surgical plan.

Modifier 58 is appended when a procedure during the post-op period was planned at the time of the original surgery, was more extensive than the original procedure, or is for therapy following a diagnostic surgical procedure. Example: a patient undergoes diagnostic arthroscopy of the knee (29870, 90-day global) that confirms a meniscal tear. The patient returns four weeks later for the planned arthroscopic meniscectomy (29881). The meniscectomy is billable with modifier 58 because it was the planned therapy following the diagnostic procedure. Modifier 58 differs from modifier 78 in intent: 58 is planned, 78 is unplanned. Modifier 58 also differs from modifier 79 in relationship: 58 is related to the original procedure, 79 is unrelated. Documentation should reference the original surgery's operative note or pre-operative plan that established the staged or planned nature of the subsequent procedure.

When a service is performed during another procedure's 90-day global period, walk this decision tree. Question one: was the service an E/M visit or a procedure? If E/M and unrelated to the surgical condition, modifier 24. If E/M and routine post-op care, no modifier; bundled into the global. If procedure, continue. Question two: was the procedure related to the original surgical condition? If unrelated (different anatomy, different diagnosis), modifier 79. If related, continue. Question three: was the procedure planned at the time of the original surgery or for therapy following a diagnostic surgical procedure? If yes, modifier 58. If no (was unplanned, addressing a complication), modifier 78. Use /tools/modifier-finder for scenario-based guidance and confirm modifier selection against payer-specific policies.

Three documentation patterns that fail audits on global-period modifiers. Failure one: chart language that contradicts the modifier. Modifier 24 appended to an E/M billed with a diagnosis code matching the original surgical condition. The audit reviewer reads the diagnosis and concludes the visit was related. Defense fails. Fix: document modifier 24 visits with diagnosis codes for the unrelated condition, not the surgical condition. Failure two: vague or generic post-op visit notes. Notes that say 'patient seen for follow-up, doing well, no concerns' do not establish whether the visit was routine post-op (bundled, no modifier) or addressing an unrelated problem (modifier 24). The audit defaults to bundled. Fix: post-op visits where modifier 24 will be billed must explicitly document the unrelated nature of the chief complaint and the work done. Failure three: missing operative note reference for staged procedures. Modifier 58 appeals fail when the original operative note does not establish the staged plan. Fix: when a staged procedure is anticipated, document the staging in the original operative note ('Patient will return for planned meniscectomy after MRI confirmation of suspected meniscal tear').

Not every orthopedic procedure has a 90-day global period. Knowing the global indicator for each code you bill is foundational to correct modifier application. Status indicator 000: zero-day global. Same-day E/M is bundled but next-day visits are not. No 24/79/78/58 needed for next-day visits. Status indicator 010: 10-day global. The 10-day window applies; modifiers 24, 79, 78, 58 apply during the 10-day window only. Status indicator 090: 90-day global. The full 90-day window applies. Status indicator XXX: no global period concept applies. Most diagnostic codes (X-rays, MRIs) and E/M codes carry XXX. Status indicator YYY: contractor-determined global. Each MAC sets the period locally; check your MAC's LCD. Status indicator ZZZ: add-on code; global period inherits from the base procedure. Use /tools/cpt-lookup to look up the global indicator for any specific code.

Common modifier-24 misses in orthopedic practices. Patient seen during global period for an unrelated injury (slipped on ice and twisted opposite knee while recovering from total joint). Often missed because the front desk does not realize the visit qualifies for modifier 24. Patient seen during global period for chronic disease management (diabetes follow-up by the same provider when the patient happens to be in the global period of an unrelated orthopedic procedure). Often missed because the provider does not realize chronic disease management is billable separately. Patient seen during global period for a problem in the contralateral or different anatomic site (post-knee patient seen for shoulder pain, back pain, hand pain). Should be modifier 24 with appropriate diagnosis. Common modifier-79 misses. Bilateral procedures performed in stages (right knee replacement followed by left knee replacement weeks later). The second knee should be billed with modifier 79 because it is unrelated to the first knee globally. Procedures on different anatomical sites during the global period of the first procedure (carpal tunnel release while patient is in global of unrelated joint replacement). Often missed because the front-end staff does not flag the global-period overlap.

Orthopedic billing is one of our highest-volume specialty lines. Our process: every encounter during a known global period is flagged in our scheduling-and-billing integration. The encounter is reviewed by an AAPC-certified orthopedic coder who evaluates whether modifier 24, 79, 78, or 58 applies based on the chart documentation. We track global-period overlap proactively rather than reactively, which captures modifier-24 and modifier-79 revenue that practices commonly miss. We also audit op-note documentation for staged-procedure language to ensure modifier 58 is supportable when needed. The dollar impact: a typical four-physician orthopedic practice has 800 to 1,200 90-day global periods active at any given time. Capturing the 8 to 15 percent of post-op encounters that warrant modifier 24, 79, 78, or 58 typically recovers $40,000 to $80,000 per year per provider in revenue that practices commonly miss. Our orthopedic billing company charges 2.49 percent of net collections with no setup fees. Use the modifier finder for scenario-based guidance on global-period modifiers and our billing guides for specialty-specific playbooks.