Not Sure if You're Billing Anesthesia Modifiers Correctly? Here's a Refresher

Modifiers are an important part of the medical coding and billing process. They are added to to CPT and HCPCS codes to provide additional or more detailed information, and for anesthesiologists, nearly every code billed is appended with a modifier. The incorrect use of modifiers, however, routinely ranks among the top billing errors for federal, state, and private payers, according to Medicare Administrative Contractor WPS GHA.

Not sure if you are using modifiers correctly? Here’s a refresher of some of the more common modifiers used in anesthesia billing, particularly for Medicare. Some commercial payers or your state’s Medicaid program may have slightly different guidelines.

The Basics

Level I modifiers comprise two numeric digits and are maintained and updated by the American Medical Association (AMA). Level II Modifiers, however, comprise two alpha digits (AA through VP) and are maintained and updated annually by the Centers for Medicare and Medicaid Services (CMS).

In addition to the two levels, modifiers also are divided into two additional categories: pricing modifiers and informational modifiers. Generally, pricing modifiers should be used first, followed by informational modifiers.

Anesthesia Pricing Modifiers

The following anesthesia pricing modifiers direct prompt and correct payment of claims by indicating who performed the anesthesia service. These modifiers should be billed in the first modifier field.

AA – Anesthesia services performed personally by an anesthesiologist.
QK – Medical direction by a physician of two, three, or four concurrent anesthesia procedures.
AD – Medically supervised by a physician, more than four concurrent anesthesia procedures. (For Indiana claims, WPS GHA will provide reimbursement for three base units plus one time unit when the physician is present on induction. If the physician does not document he/she was present on induction, WPS GHA will reimburse based on three base units without time.)
QY – Medical direction of one CRNA/AA (Anesthesiologist’s Assistant) by an anesthesiologist.
QX – CRNA/AA (Anesthesiologist’s Assistant) service with medical direction by a physician.
QZ – CRNA service without medical direction by a physician.

Anesthesia Informational Modifiers

These modifiers are for information only and should be included after any pricing modifiers. Though they don’t directly affect the pricing and reimbursement, they are critical for the billing process.

QS – Monitored anesthesia care service. (Use with anesthesia procedure codes only, and report the actual anesthesia time on the claim.)
23 – Unusual Anesthesia for a procedure which usually requires either no anesthesia or local anesthesia but because of unusual circumstances must be done under general anesthesia. (Do not report this modifier with procedure codes that include the phrase “without anesthesia” in the description or that are normally performed under general anesthesia.)

The following modifiers are used to indicate physical status during the anesthesia procedure. They also are informational only and should be used after any pricing modifiers.

P1 – A normal healthy patient
P2 – A patient with mild systemic disease
P3 – A patient with severe systemic disease
P4 – A patient with severe systemic disease that is a constant threat to life
P5 – A moribund patient who is not expected to survive without the operation
P6 – A declared brain-dead patient whose organs are being removed for donor purposes

General Informational Modifiers

The following modifiers can be used for procedures other than anesthesia, but they also might apply to procedures an anesthesiologist performs. As with the informational procedures above, these should be included after any pricing modifiers.

PT – A colorectal cancer screening test which led to a diagnostic procedure. (Medicare policy requires the deductible to be waived for all surgical procedures furnished on the same date and in the same encounter as a colonoscopy, flexible sigmoidoscopy, or barium enema that were initiated as colorectal cancer screening services. This modifier can be applied to a variety of surgical codes, but for anesthesiologists, append to anesthesia procedure code 00810 only.)
Q6 – Service furnished by a locum tenens physician.

For more information about using modifiers when billing anesthesia services to Medicare, review your MAC’s billing guidelines. (Indiana and Michigan providers can find WPS GHA modifier guidelines on the WPS GHA Modifiers webpage.) Consult provider manuals for anesthesia billing guidelines for commercial insurers.