Anesthesia Times and Billing Patterns - New Jersey Anesthesia Professionals
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Anesthesia Times and Billing Patterns

Tracking and billing anesthesia time is a complicated process, the responsibility for which rests primarily on the anesthesiologist. According to the American Society of Anesthesiologists’ 2019 Relative Value Guide, billable anesthesia time begins at the start of the anesthesia service and continues until the operation is completed. In effect, this means that anesthesia time runs from when an anesthesiologist begins to prepare a patient for anesthesia until the patient is transferred to post-operative care [1]. While anesthesia time is, by definition, continuous, most providers allow doctors to bill for discontinuous time as long as that time is not during the operation [2]. Doctors bill by unit, each of which lasts 15 minutes and usually must be billed down to the minute.

Unfortunately, the time-based method of documentation and responsibility placed on doctors often leads to improper billing procedures. A 2018 study by Sun et al. found that anesthesia times tended to cluster around 5- or 10-minute increments. For example, while roughly the same number of procedures lasted for 59 or 61 minutes, 24% more procedures lasted exactly 60 minutes [3]. While this is unusual, a 2014 study by Deal et al. suggests that these clusters could be a result of human psychology—specifically, a non-malicious tendency to prefer round numbers [4].

At the same time, Sun’s study found that anesthesia times ending in 5-minute increments were also an average of 6 minutes longer than other procedures [3]. While this does not present definitive proof of improper billing, Sun states that the confluence of these two factors is significant.

At its most extreme, improper billing can constitute fraud. A 2012 analysis by Berwick and Hackbarth found that the annual cost of healthcare fraud in the U.S. was between $82 billion and $272 billion [5]. Whether intentional or unintentional, improper billing increases the cost of care without improving care. According to the ASA, the average price per anesthesia unit was $76.32 in 2018, making even small errors in billing consequential [6].

Automated tracking systems make it easier for doctors to accurately record anesthesia times, alleviating the impulse to round. A 2013 study by Jang et al. found that the use of electronic medical records made for a more complete documentation of anesthesia. Likewise, these systems are adept at catching errors in physician’s documentation of anesthesia times [7]. According to a 2007 study by Spring et al., systems that alert anesthesiologists to errors in documentation can reduce the error rate to almost zero [8].

Electronic documentation systems can also help doctors bill for additional time. For example, many doctors begin counting anesthesia time when the patient is in-room (PIR), missing valuable preparation time. Over the course of several hundred operations, these few minutes add up to major losses, which can be averted with an electronic system that documents this pre-operative time while alerting to possible concurrency errors [9]. More broadly, the 2018 study by Sun et al. proposes transitioning from a time-based system to one that is based on fee-for-service, which the authors say would decrease billing errors and avoid the need to document anesthesia times [3].


[1] DeSocio, Peter, and Vijay Saluja. “2019 Relative Value Guide Updates Include Anesthesia Time and Field Avoidance.” 2019 Relative Value Guide, American Society of Anesthesiologists (ASA), 2019,

[2] Committee on Standards and Practice Parameters. “​Standards for Basic Anesthetic Monitoring.” ​Standards for Basic Anesthetic Monitoring, American Society of Anesthesiologists, 2015,

[3] Sun, Eric C, et al. “Comparison of Anesthesia Times and Billing Patterns by Anesthesia Practitioners.” JAMA Network Open, vol. 1, no. 7, 9 Nov. 2018, doi:10.1001/jamanetworkopen.2018.4288.

[4] Deal, Litisha G, et al. “Are Anesthesia Start and End Times Randomly Distributed? The Influence of Electronic Records.” Journal of Clinical Anesthesia, vol. 26, no. 4, 20 May 2014, pp. 264–270., doi:10.1016/j.jclinane.2013.10.016.

[5] Hackbarth, Andrew D. “Eliminating Waste in US Health Care.” JAMA, vol. 307, no. 14, 11 Apr. 2012, pp. 1513–1516., doi:10.1001/jama.2012.362.

[6] Stead, Stanley W, and Sharon K Merrick. “ASA Survey Results for Commercial Fees Paid for Anesthesia Services – 2018.” ASA Newsletter, The American Society of Anesthesiologists, 1 Oct. 2018,

[7] Jang, Junghwa, et al. “The Effects of an Electronic Medical Record on the Completeness of Documentation in the Anesthesia Record.” International Journal of Medical Informatics, vol. 82, no. 8, Aug. 2013, pp. 702–707., doi:10.1016/j.ijmedinf.2013.04.004.

[8] Spring, Stephen F, et al. “Automated Documentation Error Detection and Notification Improves Anesthesia Billing Performance.” Anesthesiology, vol. 106, no. 1, Jan. 2007, pp. 157–163., doi:10.1097/00000542-200701000-00025.

[9] Long, Gillian. “Getting Paid for All Your Anesthesia Time.” Anesthesia Provider News, Anesthesia Business Consultants LLC, 20 Oct. 2014,