Revenue Cycle Insider

FAST vs. eFAST: Do you know the difference?

A patient presents to the emergency department (ED) with abdominal pain and shortness of breath after a motor vehicle collision. The trauma to the patient’s chest must be evaluated quickly. Relocating to the computed tomography (CT) suite could delay lifesaving treatment.

In these circumstances, the ED physician must perform a focused assessment with sonography in trauma (FAST) exam, which is a noninvasive diagnostic imaging assessment that uses multiple ultrasound views to detect free fluid in the body. Physicians use FAST exams in scenarios such as blunt trauma, penetrating trauma, and blast injuries.

Keep reading to get a bead on the intricacies of FAST exam coding.

Recognize Patients Who Need a FAST Exam

FAST exams support immediate treatment decisions in hemodynamically unstable patients, avoiding the delay of relocation to the CT suite. They detect the presence or absence of free fluid, which in trauma is often blood. They are not used for detailed analysis of injuries or to estimate fluid volume, since that level of assessment may delay treatment. Trauma from falls, car accidents, and blast injuries can cause pericardial effusion (fluid in the pericardium), hemoperitoneum (blood in the peritoneum), or cardiac tamponade (when pressure on the heart affects its ability to fill).

According to a study published in Surgery, FAST exams have an overall accuracy of 94.1 percent. However, negative FAST findings do not rule out injury. Sensitivity (true positive rate) is 43 percent, meaning if there is free fluid, a FAST exam has a 43 percent probability of a positive result. Specificity (true negative rate) is 99 percent, meaning if there is no free fluid present, a FAST exam has a 99 percent probability of a negative result.

FAST exams are best used to “rule in” rather than “rule out.” Because of this, patients may receive multiple FAST exams, even if the first result was negative.   

Differentiate FAST From eFAST

There are two forms of FAST exam: the standard FAST exam and the extended FAST exam (eFAST).

A standard or traditional FAST exam consists of four views (cardiac, right upper quadrant, left upper quadrant, pelvic). Physicians use standard FAST exams to detect hemoperitoneum and pericardial effusion. Report standard FAST exams with two CPT^® codes:

• 93308 (Echocardiography, transthoracic, real-time with image documentation (2D), includes M-mode recording, when performed, follow-up or limited study)
• 76705 (Ultrasound, abdominal, real time with image documentation; limited (eg, single organ, quadrant, follow-up))

Each code represents a specific FAST exam component. You’ll use 93308 to report the limited transthoracic echocardiogram component. Echocardiography is used to check for fluid in the pericardial sac. Report 76705 for the limited abdominal ultrasound component. These views check for intraperitoneal fluid in the bilateral upper quadrants of the abdomen and the pelvis. If the entire abdomen is imaged, report 76700 (… complete) instead of 76705.

Coding tip: According to the April 2003 issue of CPT^® Assistant, report only 1 unit of 76705 for an ultrasound study covering two quadrants of the abdomen.

When a chest ultrasound is added, the FAST exam becomes an eFAST exam. An eFAST exam consists of six views (the four listed for FAST exam, plus right and left chest views) The chest ultrasound helps assess blood (hemothorax) or air (pneumothorax) in the pleural cavity.

Report an eFAST exam with the standard FAST codes (93308, 76705) plus 76604 (Ultrasound, chest (includes mediastinum), real time with image documentation).

The table below highlights the key differences between FAST and eFAST exams:

Coding tip: If a limited retroperitoneal view is also evaluated, report 76775 (Ultrasound, retroperitoneal (eg, renal, aorta, nodes), real time with image documentation; limited).

Note These Commonly Used Modifiers

When the facility owns the equipment and the physician provides the interpretation and report, you’ll append modifier 26 (Professional component) to every component of a FAST/eFAST exam.

If the same physician performs multiple FAST/eFAST exams on the same day, append modifier 76 (Repeat procedure or service by same physician or other qualified health care professional) to any FAST/eFAST exam beyond the first. For example, you’ll report a second FAST exam to assess a worsening patient with 93308-26-76 and 76705-26-76.

In the ED, the physician will nearly always perform a separately reportable ED evaluation and management (E/M) service along with a FAST/eFAST exam. Report the ED visit with an appropriate code from 99281-99285 (Emergency department visit for the evaluation and management of a patient …) or 99291-+99292 (Critical care, evaluation and management of the critically ill or critically injured patient …) for critical care encounters, which are a real possibility for a patient who needs a FAST/eFAST exam. Append modifier 25 (Significant, separately identifiable evaluation and management service by the same physician or other qualified health care professional on the same day of the procedure or other service) to any ED E/M code you report in addition to the FAST/eFAST exam. If the E/M service results in a decision for a major procedure (90-day global period), use modifier 57 (Decision for surgery) on the E/M instead.

Know Documentation Requirements to Secure Pay

To separately report imaging services, you need to include a separately identifiable, signed written report that includes indication, views, description, and impression. The provider must also establish medical necessity in the notes. The American College of Emergency Physicians (ACEP) states that only listing a FAST result as “normal” or “negative” does not satisfy documentation requirements. The images must be permanently stored or retained.

A study published by the National Library of Medicine found 27 percent of trauma patients with eFAST indications had no billed eFAST exam, either from missing documentation or lack of a separate eFAST procedure note. Each unbilled exam represents lost revenue. Based on the 2026 Medicare Physician Fee Schedule (MPFS) national payment amounts for 93308-26, 76705-26, and 76604-26, each unbilled eFAST is a loss of $79.83.

Understanding the components of FAST and eFAST exams is necessary to know which CPT^® codes apply. Complete documentation, including a separately identifiable signed written report with indication, impression, and permanent image retention is needed to code FAST/eFAST exam elements separately from any E/M service.

You also need to verify third-party payer guidelines, as bundling and modifier rules may differ among payers. With this knowledge, you can assign the correct codes for FAST/eFAST exams and successfully capture and bill the work performed.

Angela Halasey, BS, CPC, CCS, Contributing Writer