Anesthesia Modifiers, Physical Status, and Qualifying Circumstances

Like all medical coding and billing, getting the details right for anesthesia coding and billing is critical. But not only is documentation, start and end times, and code selection important, so is choosing the right modifiers, accurately indicating the patient’s physical status, and recording any other qualifying circumstances that may make a difference in how claims are paid.

Whether you’re just getting started with anesthesia coding and billing, or are a seasoned professional, this article offers a refresher on anesthesia modifiers, physical status, and qualifying circumstances.

Anesthesia Modifiers

Modifiers are two-digit codes added to CPT and HCPCS codes that provide additional or more detailed information. They are divided into two levels and two categories.

Level I modifiers comprise two numeric digits and are maintained and updated by the American Medical Association (AMA). Level II Modifiers have two alpha digits (AA through VP) and are maintained and updated annually by the Centers for Medicare and Medicaid Services (CMS). The two categories include pricing modifiers and informational modifiers. Generally, pricing modifiers should be used first, followed by informational modifiers.

Nearly every anesthesia code billed is appended with a modifier. The incorrect use of modifiers routinely ranks among the top billing errors for federal, state, and private payers, according to Medicare Administrative Contractor WPS GHA.

The following anesthesia pricing modifiers indicate who performed the anesthesia service and should be billed in the first modifier field.

AA – Anesthesia services performed personally by an anesthesiologist.
AD – Medically supervised by a physician, more than four concurrent anesthesia procedures. (Medicare 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, they will reimburse based on three base units without time.)
QK – Medical direction by a physician of two, three, or four concurrent anesthesia procedures.
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.

For medically-directed anesthesia services (up to 4 concurrent cases) that use Modifiers QK, QY, or QX, the Medicare allowance for both the physician and the qualified individual is 50 percent of the allowance for the anesthesia service if performed by the physician alone. Qualified individuals include Certified Registered Nurse Anesthetists (CRNAs), anesthesiologists’ assistants (AAs), interns, residents or a combination of these individuals.

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 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.

22 – Increased Procedural Services. This modifier is generally used when the work required to provide a service is substantially greater than typically required. Documentation must support the substantial additional work and the reason for the additional work (i.e., increased intensity, time, technical difficulty of procedure, severity of patient’s condition, physical and mental effort required). According to the ASA Relative Value Guide, this modifier can be used by anesthesiologists in instances of field avoidance and the increased work and complexity when there is limited access to the patient’s airway.
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.

Physical Status Codes

The following modifiers are used to indicate physical status during the anesthesia procedure.

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

For Medicare, these codes are informational only and should be used after any pricing modifiers. However, some commercial payers may take physical status into consideration when assigning payment. In fact, according to the ASA’s Annual Commercial Payer Survey, more than 80 percent of commercial contracts cover physical status in some way.

The following units should be used when factoring physical status into the billed price:

P1 – 0 units
P2 – 0 units
P3 – 1 unit
P4 – 2 units
P5 – 3 units
P6 – 0 units

Also, in their document “Anesthesia Payment Basics Series: #4 Physical Status,” the ASA provides examples of each physical status level.

Qualifying Circumstances

Qualifying circumstances are billed using add-on codes, rather than modifiers, that are listed separately in addition to the anesthesia code. Among those codes include the following:

99100 – Anesthesia for patient of extreme age, younger than 1 year and older than 70 (1 unit)
99116 – Anesthesia complicated by utilization of total body hypothermia (5 units)
99135 – Anesthesia complicated by utilization of controlled hypotension (5 units)
99140 – Anesthesia complicated by emergency conditions (2 units)

According to the ASA, for anesthesia codes that are specifically written for pediatric patients, it is not appropriate to also code 99100. As well, for codes 99116 and 99135, they should not be reported with cardiac procedures performed with cardiopulmonary bypass when hypothermia or hypotension may be the result of being on bypass. Finally, when using 99140, the emergency condition should be specified.

According to the ASA, Medicare also does not recognize qualifying circumstances for additional payment, though many commercial payers do. According to the ASA’s Annual Commercial Payer Survey, as many as 85 percent of commercial contracts cover qualifying circumstances in some way.