Introduction
The field of acute care surgery (ACS) continues to evolve, with ACS surgeons providing critical services across fields of trauma and emergency surgery, as well as intensive care. As the complexity of this care delivery model increases (eg, expanded surgical rescue, incorporating new procedures or technologies, working with trainees and advanced practice providers (APPs)), so do the nuanced considerations for reimbursement of services. In our complex healthcare landscape, agencies such as the Centers for Medicare and Medicaid Services (CMS) continue to update documentation and coding requirements for physicians. Although surgeons are trained in advanced clinical skills, little formal education is provided in areas of coding and billing. The modern surgeon must have a deeper understanding of these topics if they are to act as key policy stakeholders in national discussions regarding the role of payers in physician or hospital reimbursement. Understanding the requirements for accurate coding will also allow surgeons to refine their documentation and capture the complexity of the work they are already performing.
Recognizing the need for ongoing coding and billing guidance, the national professional organization for acute care surgeons—the American Association for the Surgery of Trauma (AAST)—presented an expert panel entitled “Optimizing your Output: Advanced Coding and Billing for ACS Surgeons” at the 83rd annual meeting in September 2024 (Las Vegas, Nevada). This was a collaboration between the AAST Associate Member Council (junior faculty members and trainees within the AAST), the AAST Healthcare Economics Committee and the AAST Military Liaison Committee. Led by two moderators, the aim of the panel was to provide surgeons up-to-date recommendations on topics including: coding with other physicians, trainees or APPs, critical care billing, procedural charge capture optimization and the use of modifiers. Recommendations are provided in each of these areas.
Documenting and coding with students and other providers
Surgeons frequently interact with medical students, surgical trainees, APPs, or fellow surgeons during various times in their careers. In each of these interactions CMS has defined rules regarding how evaluation and management (E&M) or Current Procedural Terminology (CPT) billing is performed. E&M coding is used to capture the various services centered around the evaluation and management of patients such as consultations, physical examination and medical decision-making (MDM). This is in comparison to CPT coding which is used for procedural or surgical care provided to patients. Understanding these differences and the CMS requirements will allow surgeons to capture reimbursement for care provided by collaborators whereas avoiding insufficient documentation or inappropriate charges.
Trainees–students/residents/ACGME fellows
The most recent version of the Medicare Claims Processing Manual provides formal definitions of who qualifies as a resident or student. Per CMS:
A medical student is defined as “an individual who participates in an accredited educational program (e.g. a medical school) that is not an approved graduate medical education (GME) program.1” Similarly, a resident or fellow is “an individual who participates in an approved GME program or a physician who is not in an approved GME program, but who is authorized to practice only in a hospital setting.1”
Teaching physicians can provide billing attestations for both groups, but CMS dictates specific rules regarding which portions of the care providers are required to participate or supervise.
E&M services
In 2018, CMS updated the requirement for student notes allowing them to be part of the billable record if the student contribution was performed in the physical presence of a teaching physician or resident. Otherwise, the teaching physician must repeat the entire examination. Teaching physicians must verify and attest to the accuracy of all the student documentation in addition to being present with the student or performing the examination themselves. A teaching attestation that clearly states the attending’s contribution must be added to the students’ note to qualify as billable documentation. Simply stating the provider was present or supervised the student is insufficient. A sample attestation can be seen in table 1.
Sample documentation for various E&M and CPT services
For residents and fellows, teaching physicians are not required to duplicate all the portions of the examination. Resident and fellow notes are billable as long as (1) the teaching physician was present for the critical/key portion of the service or performed this portion themselves and (2) the teaching physician has personal involvement in patient management. See table 1.
CPT or procedural services
Teaching physicians may bill for procedures or operations performed by students, residents and fellows, but specific criteria apply depending on the duration of the procedure and have varying requirements for documentation.
For minor procedures lasting less than 5 min, the teaching physician must be present for the entire procedure and document as such. Only residents/fellows can document this procedure and have it attested by the attending. In cases where a student performs the procedure under direct supervision, the teaching physician must complete the procedural documentation. If the teaching physician is not present for the entire procedure, the service is not billable.
For major procedures or operations, the teaching physician must be physically present for the key portions of the case and immediately available for the entire case. Residents/fellows may document the procedure with attending attestation, but cases performed by students still must be documented by the teaching physician. In these situations, if the surgeon was not physically present for the entire operation, it must be noted in the attestation they were physically present for the key portions.
Per CMS for both E&M and CPT coding, the critical or key portion of the service is determined by the teaching physician and may vary from case to case and diagnosis to diagnosis. For both student and resident/fellow notes, when billing for these documents, a GC modifier should be added to the E&M code. This is a non-financial modifier that does not add or subtract reimbursement from the service, but tags the encounter as having been performed in part by a resident under the direction of a teaching physician.
Attending surgeons
There are several circumstances where a surgeon may perform an operation or co-manage a patient with another attending surgeon. Although CMS does not permit duplicate billing for the same services, there are situations in which CMS will reimburse both providers given certain conditions are met.
CPT or procedural services
The cosurgeon (modifier 62) modifier applies to situations in which you have two surgeons of the same or different specialties working together to perform a procedure with a single procedure code (ie, ventriculoperitoneal shunt placement, lumbar spine exposure/repair) or two surgeons working simultaneously on different body parts (ie, bilateral knee replacements) to reduce total anesthetic time.
Both surgeons must dictate their own operative report in which they indicate the case was a cosurgery and list the name of the cosurgeon involved. The notes must list the medical necessity for two surgeons and provide a report of the distinct work performed by the dictating surgeon. CMS does limit which cases are eligible for a cosurgeon and whether a cosurgeon is allowed to be from the same specialty. A complete list of qualifying CPT codes can be found in the Medicare Physician Fee Schedule (MPFS).2 If all of these criteria are met, then the cosurgeons will be reimbursed for up to 125% of the allowed amount divided between each surgeon (62.5% for each provider). A link to the Physician Fee Schedule Relative Value Files can be found here: https://www.cms.gov/medicare/payment/fee-schedules/physician/pfs-relative-value-files
Many surgical cases require a surgical first assist to aid the primary surgeon in completion of the case. If the first assistant is an attending surgeon, CMS does provide a partial reimbursement to the assisting surgeon through the surgeon assistant modifiers (modifiers 80/82 and modifier 81). Modifier 80 applies to non-teaching hospitals whereas modifier 82 is used for teaching hospitals. To qualify, the primary surgeon dictates in the operative report that a second attending presence was required due to the lack of a qualified resident/first assist in addition to noting why and how the assisting surgeon helped in the case (see table 1). The assisting surgeon is not required to document anything. In these situations, the assisting surgeon is reimbursed 16% of the MPFS fee amount.
Modifier 81 is used for situations when there may be a qualified assistant, but an assisting surgeon still helps the primary surgeon for a short portion of the case (as opposed to the whole case for modifiers 80/82). An example would include assisting with the cholangiogram on a difficult gallbladder. Again, the primary surgeon should note why and how the assisting surgeon helped in the case. The assisting surgeon is not required to document anything. In these situations, the assisting surgeon is reimbursed 16% of the MPFS fee amount.
Advanced practice providers
In addition to students and residents, many trauma and ACS programs are supported by APPs such as nurse practitioners and physician assistants. As licensed independent practitioners, APPs are able to document and bill for their own services and CMS will reimburse their care to 85% of the allowable MPFS. If both an APP and a physician are involved in the care of a patient, however, and document their contributions to the visit, a split share claim can be applied. This allows for the visit to be billed under either the physician or the APP depending on who performed the substantive portion of the care. Prior to 2024 the substantive portion of the visit was defined as the provider who performed greater than 50% of the total visit time. A recent CMS update expanded the definition for substantive portion to include either the majority of the total time or the substantive portion of the MDM.
To optimize charge capture it is always preferable to bill the visit under the physician as this will result in 100% MPFS reimbursement. It is crucial however that the physician actually provide the substantive portion of the care and document as such in their attestation. A full discussion of optimizing when and how to perform split share billing is beyond the scope of this review, but has been extensively reviewed in the medical literature including recommendations since the 2024 update.3 4
Leveling up: maximizing your medical decision making
Prior to 2021 when performing an E&M visit, physicians were required to document a complex and often tedious list of elements including history of present illness, review of systems, and physical examination each which had multiple subsections of associated data. In 2021, however, CMS simplified E&M visit requirements to the MDM system which relies on three elements—number/complexity of problems addressed, amount or complexity of data reviewed, and risk of complications. Each of these criteria has three levels (low, moderate, and high) with your overall MDM based on the highest of the two out of the three criteria. The MDM system places greater emphasis on clinical decision-making and patient/disease-related factors as compared with the previous metrics which assigned value for increased documentation without actual clinical relevance.
With the transition to this new system, however, it is important for providers to have a clear understanding of what elements need to be documented to help raise their level of MDM and achieve a higher billing group. Many of the items that we do as part of the standard review of a patient are assigned value for MDM, but are not things which we would naturally document. For example, to achieve the highest level in the data criteria it must be explicitly documented that specific test results were reviewed, or imaging was interpreted. In the era of electronic medical record auto-text, simply having the CT report or a table of recent labs auto-populate into your note is not sufficient. Instead, the practitioner must explicitly state and reference the data they reviewed and interpretation of that data in their MDM section. Creation of MDM templates with prepopulated lists of the requirements for each of the three elements can help physicians optimize their documentation and ensure credit is assigned for the management they are performing.
Optimizing E&M and procedural coding: modifiers make it happen
Modifiers are codes used to indicate that the care a physician provides is outside of the normal expected services. Modifiers exist for both E&M and CPT codes and are a key tool in optimizing your reimbursement.
E&M modifiers 24, 25, 57 and FT
These are essential codes for E&M documentation in the postoperative global period. Although physicians cannot bill for issues directly related to the operative procedure during the global period, management of unrelated conditions, such as medical comorbidities, is billable services. Understanding what is covered and the length of the global period is crucial for appropriate reimbursement. Depending on the type of procedure, the length of the global period may vary (see table 2). Smaller procedures and minor operations often have shorter global periods that allow for more extensive postoperative billing.
Global periods for various procedures and operations
For patients within a global period, modifier 24 should be added to E&M documentation to indicate that the physician has provided services unrelated to the operation. Modifier 25 is used for E&M services performed on the same day as the surgical procedure.
Common examples of care provided within a global period that would qualify for a modifier 24/25 would include management of a patient’s anticoagulation, starting or holding their home diabetes medication in the setting of altered oral intake postprocedurally, or management of postoperative cardiac arrhythmias. Physicians must document not only the diagnosis of the unrelated condition they are managing but provide support that its management is distinct from the operation and not routine postoperative care. Examples of common conditions and management justification can be found in table 3.
Medical diagnoses and justification for modifier 24
When attesting to a modifier 24 the physician should select their E&M level based only on the non-operative care they provide. Although a patient may be surgically complex, if the only care you provide outside of the surgical is relatively simple (titrating blood pressure medications) you should only bill for a low E&M visit with a −24 modifier.
If patients are admitted to the intensive care unit (ICU) postoperatively and care is provided by the same team who performed the operation, a −FT modifier should be added to code for services provided unrelated to operative care. The −FT modifier functions similarly to the −24 modifier, but specifically applies to patients admitted to the ICU.
Similarly on the day a patient has an operation, physicians are not able to bill for E&M because the global period is activated. Preoperative evaluation and the decision for operation however is a billable service and the addition of modifier 57 will allow for the surgeon to bill for their preoperative E&M services for that day.
A summary of common E&M modifiers can be found in table 4 including modifiers that may increase reimbursement for operative procedures.
Common E&M and CPT modifiers
Procedural and operative modifiers 22, 51, 58, 59, 78 and 79
CMS pays a set fee called a global package for the given procedural CPT. CPT modifiers are used to indicate the services provided extend beyond what is covered in a given global package. Modifier 59 for example, is used to indicate distinct and separate procedures performed at the same time. For example, a left thoracotomy and left tube thoracostomy are one procedure as the thoracostomy tube is a bundled portion of a thoracotomy service, but a simultaneous right tube thoracostomy is a distinct procedure and modifier 59 applies. With a modifier 59 the physician is reimbursed for both procedures.
Modifier 51 is used for multiple procedures performed on the same organ system such as a skin excision with a subsequent complex repair. This code indicates separate but related procedures and whereas only one CPT code can be the primary, the related procedure will also be reimbursed, but at a reduced rate.
For planned staged procedures such as damage control laparotomies, the addition of modifier 58 allows for full payment for each of the subsequent procedures, but does reset the global period to the most recent operation. Comparatively, modifier 78 is used for unplanned returns to the operating room for minor or major complications by the initial surgeon. This code does not reset the global period, but does result in a 20% payment reduction. For patients who require a subsequent operation within their global period that is unrelated to their initial operation, adding modifier 79 allows for reimbursement for the second procedure. An example would be a patient who had a trauma laparotomy and now requires a tracheostomy. If performed by the same physician (or physician group) modifier 79 allows for full reimbursement for the tracheostomy and initiates a second global period for the tracheostomy without resetting the global period for the laparotomy.
Modifier 22 is an often-used, but frequently non-reimbursed CPT code that is used to indicate that the work performed for a given procedure was substantially greater than what is typically required. When accepted, this code entitles the physician to increased reimbursement above the traditional Medicare Fee Schedule.5 The exact increase in payment is insurer specific. Achieving this reimbursement however requires meticulous documentation and must include a discussion of the unique patient factors, technical aspects, and time comparisons versus a typical procedure that made this procedure substantively greater work. Care should be taken to use modifier 22 only when clinically appropriate and to ensure adequate documentation as claims with a modifier 22 attached have a higher rate of denial from CMS and private insurers.3
Optimizing critical care billing
As compared with E&M billing, critical care reimbursement is determined by time-based service with a minimum of 30 min of critical care time required to qualify for the first level of reimbursement. Although a strict time-based fee schedule may seem inflexible, there are multiple ways to optimize critical care charge capture.
The first thing to note is that critical care does not need to be delivered in an ICU. If a surgeon provides a critical care level of service in the emergency department or floor setting, the cumulative time across all these settings can be billed. This is especially pertinent for trauma and acute care surgeons who perform active resuscitation in multiple locations around the hospital. Similarly, if a patient is transferring out of the ICU, but has ICU needs which are addressed prior to their transfer later in the day, the physician may still bill for the time.
Importantly, only time spent directly on patient care is included and excludes education of learners and updating family members. Time spent discussing management decisions with family or power of attorney when the patient is unable to participate in decision-making can be included in billable critical care time.
Critical care time includes the direct care of the patient and a variety of bundled procedures that cannot be billed separately. There are, however, several common procedures that are not included in the critical care billing bundle (see table 5). For each procedure, appropriate documentation with the diagnosis, clinical justification and procedure details will allow the physician to bill for these services. Time spent performing these separately billable procedures cannot be included in the billed critical care time.
Common bundled and unbundled critical care procedures
Another commonly missed critical care charge is the professional component of an image-guided procedure. Performing a Focused Assessment with Sonography for Trauma (FAST) or a cardiac echogram in the ICU is its own billable procedure, but the subsequent interpretation of that examination by the physician is a separate charge which is captured by adding modifier 26. CMS has specific criteria regarding image documentation, results interpretation, and recording which need to be met to qualify for this charge. Ultrasound guidance of pigtail catheters, chest/abdominal ultrasound, interpretation of intraoperative fluoroscopy, and ultrasound central line placements are examples of procedures with a professional component.
