Anesthesia Coding Alert

Let patient-specific details guide your choice.

Modifier 23, unusual anesthesia, monitored anesthesia care, special circumstances, modifier AD, medical necessity, G20, F70, F79, G80, F40

Although every anesthesia case is unique, they carry commonalities from a coding standpoint: You select the most appropriate code, calculate time units, and append explanatory modifiers. Sometimes, however, your anesthesiologist provides service above and beyond the norm for a case—which could mean you’re justified in appending modifier 23 (Unusual anesthesia) to the procedure code.

Important starting point: Reporting modifier 23 does not affect your reimbursement. It does help your claim be as accurate as possible, which should be every coder’s goal.

The next time you find yourself considering modifier 23, heed our experts’ advice and follow these four steps to ensure your claim meets certain criteria and won’t be denied.

1. Understand What Constitutes ‘Unusual’

Many coders might simply refer to modifier 23 by its short descriptor: “Unusual anesthesia.” Take a closer look at its full description in Appendix A, however, and you’ll gain 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.”

Putting the definition to work: Verify that the claim in question meets three criteria before you append modifier 23:

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

2. Dig Into the Unusual Circumstances

If the other physician requests anesthesia for the procedure, be sure your anesthesia provider documents why the patient needed anesthesia. Underlying conditions that help justify anesthesia range from Parkinson’s disease (G20.x) and mental retardation (F70-F79) to claustrophobia (F40.240) and cerebral palsy (G80.x).

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

Tip: Be sure physicians document the reason anesthesia was necessary. Any way you can substantiate the medical necessity for using anesthesia will help when you file the claim.

“Sometimes it’s necessary to use general anesthesia on children, rather than local,” Brink adds.

For example, a normal healthy adult does not usually require anesthesia for an MRI, says Kelly Dennis, MBA, ACS-AN, CANPC, CHCA, CPC, CPC-I, owner of Perfect Office Solutions in Leesburg, Fla. However, a pediatric patient may be unable to stay still for as long as the procedure requires and often receives general anesthesia.

3. Verify That General Anesthesia Was Used

The physician or CRNA must administer general anesthesia— not regional or 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,’” Dennis says.

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 operating room, however, which means an anesthesia provider is present.

Documentation: Verify that the documentation from your providers supports the substantial additional work and the reason for the extra time (increased intensity, technical difficulty, severity of the patient’s condition, etc.).

4. Get Familiar with the Payer’s Rules

Some insurers have their own guidelines for when you should report modifier 23, Dennis says, which means you should always check those before submitting the claim. A few examples of specifications 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.