Anesthesia Coding Alert

Keep this formula for reimbursement handy.

Anesthesia billing is a process that involves several components, one of which is the calculation of time units. Accurate anesthesia time unit calculation is essential for proper reimbursement and compliance with billing standards.

This article provides an overview of anesthesia time units, their calculation, and best practices for ensuring accuracy.

Define Anesthesia Time Units

Anesthesia time units are a key element in the billing process for anesthesia services. The Relative Value Guide, published by the American Society of Anesthesiologists (ASA), defines anesthesia time as “the period during which an anesthesia practitioner is present with the patient. It starts when the anesthesia practitioner begins to prepare the patient for anesthesia services in the operating room or an equivalent area and ends when the anesthesia practitioner is no longer furnishing anesthesia services to the patient, that is when the patient is safely placed under postoperative care.”

Time units represent the duration of anesthesia care provided to a patient, measured in increments that vary depending on the payer’s policies. Most payers define 1 unit as equivalent to 15 minutes of time, but some payers calculate units based on 10 minutes of time. It is important to be familiar with all your payer policies. Time units, combined with base units and any applicable modifiers, determine the total reimbursement for anesthesia services.

Know Components of Anesthesia Billing

The reimbursement for anesthesia services typically depends on the following factors:

• Base unitsreflect the complexity and intensity of the anesthesia procedure, regardless of time.
• Time units account for the duration of anesthesia care.
• Modifiers account for adjustments based on specific circumstances, such as physical status or emergency indicators. Some payers, such as Medicare, do not reimburse for certain modifiers.
• Conversion factor is the dollar amount assigned per unit. This amount varies for each payer and is based on individual contracts between payers and providers, or on geographic location, such as with Medicare and Medicaid.

The formula for calculating anesthesia reimbursement is:

Total Reimbursement = (Base Units + Time Units + Modifiers) × Conversion Factor

Calculate Anesthesia Time Units Like This

Time units are calculated based on the duration of anesthesia care, outlined in the Relative Value Guide definition above. Here’s how the calculation works:

1. Determine Start and End Times
   Record the exact time anesthesia care begins, and the exact time the anesthesia care ends. This time should not be rounded, but recorded in exact minutes.
2. Calculate Total Minutes
   Subtract the start time from the end time to determine the total minutes of care provided.
3. Convert Minutes to Time Units
   Divide the total minutes by the payer’s defined time unit increment, such as 15 minutes per unit, or the amount defined by the payer policy.
   Round the result according to the payer’s guidelines.

For example, if a procedure lasts 60 minutes and the payer defines 1 unit as 15 minutes, the time unit calculation would be:

60 minutes ÷ 15 minutes/unit = 4 time units

Don’t Miss These Key Considerations

While there are formulas that apply to calculating time units, it’s important to be aware of some additional elements that can affect your results.

These elements include:

• Payer-specific guidelines: Different payers (Medicare, Medicaid, private insurers) may have unique rules for time unit calculation. Always refer to the specific payer’s guidelines.
• Accurate documentation: Detailed and accurate documentation of start and end times is critical. Ensure that all records are consistent and legible.
• Rounding rules: Follow the rounding policies specified by the payer. Some payers allow rounding to the nearest whole unit, while others may require rounding to the nearest tenth.
• Continuous monitoring: Time spent by the anesthesia provider providing continuous monitoring and care is billable. Periods when care is interrupted or paused should not be included in the time calculation.

Beware Common Challenges and Incorporate These Best Practices

It’s important to keep an eye out for inconsistent documentation. Failure to document start and end times accurately can lead to claim denials or audits. This may also extend the time needed for the billing staff to submit the claim to the payer if a provider query to determine accurate time is necessary. Not having a clear picture of payer policies can also be problematic — misunderstanding payer-specific guidelines can result in incorrect billing. And, of course, check your numbers. Errors in rounding may lead to overbilling or underbilling.

There are some steps you can take to make sure your anesthesia time unit calculations are as accurate as possible:

• Make sure your staff is trained: Ensure that all anesthesia providers and billing staff are educated about proper documentation and calculation methods.
• Complete audits regularly: Conducting periodic audits of anesthesia billing records can identify and help you address errors.
• Stay on top of updates: It’s important to regularly review payer policies and industry standards to ensure compliance.

Anesthesia time unit calculation is a critical component of the billing process that requires precision and attention to detail. By understanding the calculation method, following payer guidelines, and implementing best practices, healthcare providers can ensure accurate billing and avoid potential compliance issues. Proper documentation and regular training are key to maintaining the integrity of anesthesia billing practices.

Julie McDaniel, MHA, CPC, CANPC, Vice President of Operations at Rock Medical Practice Solutions