Why Is Time Important When Billing for Anesthesia Services?

How Inaccurate Time Reporting Can Result in Claim Denials

The core of billing for anesthesia is based on time. It must accurately represent the time spent caring for the patient while prepping, during, and completing any anesthesia procedures. Time is of the essence, literally. Documentation and accuracy in coding and medical billing are essential to submitting clean claims and avoiding denials. Avoiding claim denials with anesthesia billing depends on meticulous attention to time reporting, from the start to the stop time, and with explicit consistency.

Two simple approaches to time reporting can help to avoid claim denials: using the 24-hour clock and documenting the start and stop times with the same timepiece.

If an anesthesiologist starts documenting time on a 12-hour clock but stops the time with the 24-hour system, the reported total time may appear fabricated. A start time of 2:00 or 1400 is decidedly different, creating significant inaccuracies in the total time on a claim.

Using a clock to start documenting time and a watch to end the time may result in reporting more or less time than was spent in anesthesia. The most accurate method of reporting time is through the electronic health record, which provides a computer-based recording time. Avoid using different methods for documenting time.

Things to Consider When Billing for Anesthesia Services

coronis health anesthesiologist medical biller's office with IV machine

Billing for anesthesia services may be complex, but following the guidelines that set the stage for compliance will help to prevent claim denials. Fundamentally, anesthesiologists have rules that govern what they can bill for and what may trigger a claim denial or audit.

While a preoperative evaluation is necessary, anesthesiologists cannot record billable time for this process.

Documentation of time must not be altered; if a patient's anesthesia starts at 0647, the anesthesiologist cannot round the time up to 0650.
- Excessive documentation of five-minute increments (which may include consistent rounding) could result in billing audits.
- Audits showing more than 20% of rigid five-minute increments are considered non-compliant.
Documented time represents the uninterrupted period from the start of monitored anesthesia to the point where the anesthesiologist is no longer attending to the patient.
The end time includes the patient being transferred to a post-anesthesia care unit (PACU) with a trained nursing team.

Being scrutinous with anesthesia billing is as important as billing for other medical services. The time component is one of the most important considerations to ensure that billing is compliant and accurate to facilitate maximum reimbursement.

Tips for Calculating Anesthesia Billing Time

Insurance payers set parameters for anesthesia billing, usually adhering to strict increments of 10, 12, or 15 minutes per unit. Anesthesia billing time limits ensure that providers meticulously document the time spent monitoring the patient. The formula for calculating anesthesia units is simple enough but must be precise.

Anesthesia Billing Time Formula

Anesthesia billing time units are calculated by the provider, an anesthesiologist, or a certified registered nurse anesthetist (CRNA). Billing anesthesia time units include:

Base factor – that codes are provided by the Centers for Medicare and Medicaid (CMS) and are updated annually. This can include the preoperative evaluation but is not part of the documented time under anesthesia.

Total time units – these units refer to the time the patient spent under monitored anesthesia. The numbers are not rounded (actual time is recorded).

Calculate the formula by adding the base factor CPT code and the total time units, usually in 15-minute increments. If a procedure is 60 minutes, the total time units would be 4. Anything over 60 minutes, such as 64 minutes, would be 4.27 units (4 minutes divided by the 15-minute increment).

Conversion factors are included in the formula and assigned by CMS based on the facility's location. Modifiers are included, such as when a procedure is interrupted. The final formula includes all of these components:

For an anesthesiologist or CRNA:
- (Base factor + total time units) x Anesthesia Conversion Factor x Modifier Adjustment = Allowed amount for the anesthesiologist or CRNA

For anesthesia provided by the attending physician/surgeon:
- [(Base factor + total time units) x Anesthesia Conversion Factor] x Modifier Adjustment = Allowed amount for the provider(s)

Coding and time totals in anesthesia billing require a conscientious effort to engage in accurate documentation. The variation of time units across the landscape of anesthesia billing demands nothing less than 100% accuracy to receive maximum reimbursement for rendered services.

coronis health anesthesiologist administering medication to patient

Which Anesthesia Services Should be Billed vs. Not Billed?

Anesthesia medical billing includes a precise method of documentation and calculation. Certain components of the process are not billable when:

A patient is in a holding area or a patient lobby (included in the base factor)
A patient receives antibiotics or blood products (such as a blood transfusion, typically done at another facility)
A patient is transferred into the PACU
Non-anesthesia deliver local anesthesia

Billable services include:

Evaluation of the patient before administering anesthesia
Actual time spent under monitored anesthesia