Claims processing for anesthesia, a unique specialty, requires coding expertise in both CPT Surgery as well as ASA coding systems.  Knowledge of human anatomy and surgery coding guidelines are foundational. Considering that ASA codes are cross-walked from the Surgery CPT coding system, the coder will first identify the correct surgical CPT code and then assign the ASA code as derived from the CPT code.

The anesthesia coding process is to be executed as meticulously as the surgery itself, failing which claim reimbursements are impacted. Here are the top five pitfalls we advise coders and billers to watch out for.

Improper understanding of the surgical approach

Various approaches and techniques are utilized during a surgery; varying with the patient. The ASA code can change depending upon the approach. Identifying the surgical approach correctly from the anesthesia record, then zeroing in on the most appropriate CPT code for that approach and surgery, and finally assigning the correct ASA code as provided in the Anesthesia Crosswalk is critical. Improper selection of surgical approach can affect reimbursement, as the Base Value of the corresponding ASA code differ for each approach. As an example, mitral valve repair can be accomplished either using the transcatheter (CPT 33418) or open approach (CPT 33425). The Base Unit for the transcatheter approach is 15 (ASA code 00560), while the Base Unit for the Open mitral valve repair can either be 20 (ASA 00652) or 25 (00561 and 00563).

Missing to choose the ASA with the highest base unit

When more than one surgical procedure is performed in the same operative session, the ASA code with the highest Base Unit should be selected. Time units will equal the total anesthesia time for performing all the procedures. If the coder does not check either the Base Units of all the procedures or if the ASA code is selected based on bad practice assumption, the resultant incorrect ASA code with a lower Base Value can be selected, and the service provider ends up receiving a lower claim reimbursement.

Missing to append the correct modifiers with the ASA codes

Modifiers pay a key role in anesthesia coding and reimbursement, and can be classified into: Anesthesia Pricing, Preventive Screening, and Informational Modifiers. Pricing Modifiers affect anesthesia reimbursement and should be appended first, to include modifiers AA, AD, QK, QX, QY, and QZ. The consequences of incorrect modifier being appended, or the Pricing Modifiers not being appended first, affects the claim reimbursement. Preventive Screening modifiers, if applicable, should follow Pricing Modifiers and include Modifiers 33 and PT. They identify anesthesia services for colonoscopy screening. Informational Modifiers are for informational purposes and will not affect reimbursement in all cases. They should be sequenced in the last position. QS, AQ, and GC are examples of Informational Modifiers. While Medicare payment guidelines for anesthesia modifiers are the same, the private payers and some Medicaid plans may have their own interpretation and guidelines for usage and payment for these modifiers.

Missing to code the most compatible ICD-10-CM diagnosis code from the anesthesia record

The anesthesia record is a valid source document for diagnosis information as well. In cases of a conflict between the diagnosis of anesthesiologist and the attending physician, the attending physician should be queried for clarification (Coding Clinic 2000, second quarter, p. 15). It’s important to also code additional comorbid conditions that can affect the patient’s treatment plan and prognosis as documented in the anesthesia record.

Missing to report qualifying circumstances and physical status modifiers

Though Medicare does not recognize these codes and modifiers, most private payers and some Medicaid programs recognize these and pay additional base units for them, if appended and submitted correctly in the claim form. Hence, not appending these modifiers, may affect the anesthesia reimbursement. A clear understanding of payer-specific guidelines is essential. Coders should also be clear when to report these modifiers and where to look for such information in the anesthesia record.

Anitha Balasubramanian is currently on the core team of Quintessence Business Services & Solutions. She has deep domain experience of over 23 years in the US HealthCare Coding business. She was amongst the first batch of CPC-certified coders outside the USA.