CPT Modifiers 22, 23 and 24 in Medical Billing and Coding

In medical billing and coding modifiers are the keys to 'telling the story' of a patient encounter to insurance payers. While CPT codes define what was done, modifiers explain how or where the service was performed. This reference highlights four critical modifiers used to report increased procedural effort, unusual anesthesia, unrelated E/M services during global periods, and the distinction between professional and technical service components

CPT Modifier 22: Increased Procedural Service

• Definition: Indicates that the work required to perform the procedure was considerably greater than that usually required for the standard procedure as described by the CPT code.

• Usage: This modifier is appended to the procedure code. It signifies that the procedure took substantially more time, effort, and complexity than typical due to factors like anatomical difficulty, unusual patient condition, or technical challenges (e.g., severe scarring, obesity, or an unexpected finding requiring extensive dissection).

• Documentation Requirement: Modifier requires extensive supporting documentation in the medical record to justify the increased work. This documentation must clearly explain why the service required more effort (e.g., operative notes detailing the unusual circumstances).

• Reimbursement Implication: Use of modifier often results in increased reimbursement, but payers review it carefully against the operative report.

  
  

Example: A physician performs a standard skin biopsy (). Due to excessive scar tissue and a very deep, difficult-to-access lesion, the procedure took three times as long and required advanced techniques not typical for this code. The coder might report .

Coding Tip-

• The "Rule of 25%": While not an official CPT rule, many payers won't even consider a 22 modifier unless the documentation proves at least a 25% to 50% increase in time or effort.

• Avoid "Complications": In your operative report, avoid simply saying "there were complications." Instead, use descriptive words like extensive, hemorrhaging, dense adhesions, or failed previous surgery.

CPT Modifier 23: Unusual Anesthesia

• Definition: Indicates that anesthesia was used for a procedure in an unusual, non-routine circumstance.

• Usage: This modifier is appended to the procedure code when the anesthesia required is significantly greater or unusual compared to what is typically needed for that specific procedure.

• Important Note: Modifier is used only when the procedure itself is being billed by the physician providing the anesthesia (which is rare for many surgeons or other providers, as anesthesia services are typically billed separately by an anesthesiologist using their own CPT codes). Furthermore, this modifier has largely been retired or made obsolete by many major payers (including Medicare) because the complexity of the anesthesia is better captured through ASA (American Society of Anesthesiologists) physical status modifiers and time units reported by the anesthesiology department itself.

Coding Tip-

• The "Pediatric/Special Needs" Exception: While you noted it's largely obsolete for surgeons, it is still occasionally used when a procedure that normally requires no anesthesia or local anesthesia (like a simple CT scan or a stitches removal) must be done under general anesthesia because the patient is a small child or has a psychiatric condition that prevents them from staying still.

CPT Modifier 24: Unrelated E/M Service by the Same Physician During the Postoperative Period

• Definition: Indicates that an Evaluation and Management (E/M) service provided by the same physician during the postoperative global period was unrelated to the original procedure.

• Usage: This modifier is appended only to an E/M code (e.g., ). It tells the payer, “I know this patient is in their 90-day global period for the surgery I performed, but this specific office visit is for a new, unrelated illness or injury.”

Example: A surgeon performs knee replacement surgery. Six weeks into the global period, the patient returns for treatment of a common cold. The surgeon would bill the E/M code for the cold visit appended with modifier.

Coding Tip-

• Diagnosis Codes (ICD-10): This is the "secret sauce" for getting paid. The ICD-10 code on the E/M claim must be different from the one used for the original surgery. If they match, the payer's system will automatically deny the claim as "included in the global package."