Anesthesia Coding Alert

Tip: Watch for patient-specific details to support unusual circumstances.

If your anesthesiologist provides service above and beyond the norm for a case, you might be able to append modifier 23 (Unusual anesthesia) to the procedure code. Reporting modifier 23 doesn't affect your reimbursement, but payers do have rules regarding modifier 23's use. Follow these four steps to ensure your claim meets certain criteria and won't kick back as an automatic denial.

1. Dissect the Descriptor

The abbreviated descriptor of modifier 23 in CPT®'s front cover is basic enough: It's just "Unusual anesthesia." But a closer look at its full description in Appendix A, however, gives more details you should consider:

"Occasionally, a procedure, which usually requires either no anesthesia or local anesthesia, because of unusual circumstances must be done under general anesthesia. This circumstance may be reported by adding the modifier -23 to the procedure code of the basic service."

What this means for you: Verify that the claim in question meets three criteria before appending modifier 23:

• Anesthesia used when it's normally not necessary for that procedure;
• Anesthesia used because of unusual circumstances;
• General anesthesia (instead of monitored anesthesia care, or MAC).

2. Focus on Unusual Circumstances

If the other physician requests anesthesia for the procedure, be sure your provider documents why the patient needed anesthesia. Underlying conditions that help justify anesthesia range from Parkinson's disease (332.x) and mental retardation (317-319) to claustrophobia (300.29, Other isolated or specific phobias) and cerebral palsy (343.x, Infantile cerebral palsy; or 437.8, Other ill-defined cerebrovascular disease).

The patient's age can also help justify anesthesia, such as when a small child has an MRI or needs extensive suture removal.

"Make sure physicians document the reason anesthesia was necessary," says Catherine Brink, BS, CMM, CPC, CMSCS, president of Healthcare Resource Management, Inc., in Spring Lake, N.J. "Substantiate the medical necessity for using anesthesia."

"Sometimes it's necessary to use general anesthesia on children, rather than local," Brink adds.

3. Verify General Anesthesia

The physician or CRNA must administer general anesthesia, not monitored anesthesia care (MAC), for the procedure before you can consider modifier 23.

"By definition, the 23 modifier indicates 'a procedure which usually requires no anesthesia or local anesthesia, but because of unusual circumstances must be done under general anesthesia,'" says Kelly Dennis, CPC, owner of Perfect Office Solutions in Leesburg, Fla.

As with the unusual circumstances mentioned above, factors such as the patient's age or physical status can help justify general anesthesia instead of MAC during a procedure. The extent of the service or length of time necessary can also justify general anesthesia.

Example: Most debridements only require a local anesthetic, and can be completed at the patient's bedside. A physician might choose to complete a more extensive debridement in the OR, however, which means an anesthesia provider is present.

4. Check the Payer's Rules

Some payers have their own guidelines for when you should report modifier 23, Dennis says. A few examples include:

• Listing modifier 23 in the second position and filing the claim with documentation
• Requiring modifier 23 to indicate a physician's presence for induction when used with modifier AD (Medical supervision by a physician: more than four concurrent anesthesia procedures)
• Requiring modifier 23 to indicate that a vaginal or cesarean delivery lasted longer than four hours.

Appeals help: Knowing the rules doesn't lead to automatic acceptance, so you can find yourself appealing claims with modifier 23. When that happens, emphasize the medical necessity for general anesthesia during the procedure, such as the patient's mental or physical status or age. Also include a letter of medical necessity from the primary care physician or surgeon to help bolster your position.