Mohs Surgery Workforce Continues to Increase

Roxanne Nelson RN, BSN

May 08, 2023

SEATTLE — At least for now, the number of physicians trained to perform Mohs surgery is not only stable but appears to be increasing. New findings show that the number of new fellows offsets the attrition rate and has been the case for the past 5 years.

Using CMS billing codes as a surrogate, the researchers found that there was a steady increase in the number of physicians who billed from 2015 to 2020. With the exception of 2020, which was the height of the COVID-19 pandemic, the number of times that a specific code was billed for increased on average by 4.7% annually.

"Thus, if the attrition rate remains stable, even with changes in board certification and potential payor eligibility restrictions, the number of physicians will continue to increase,” said study author Ji Won Ahn, MD, who specializes in dermatology and Mohs surgery at University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania. 

The study results were presented here at the American College of Mohs Surgery (ACMS) 2023 Annual Meeting.

The growth in the number of Mohs surgeons has been fueled by several factors, including a rising incidence of skin cancer as well as the superior cure rates and cosmetic outcomes with the procedure. Reimbursement has been favorable and training pathways have expanded. A 2019 retrospective study reported that there were 2240 dermatologists who performed Mohs surgery in the United States, with nearly all of them (94.6%) residing in metropolitan areas.

Ahn explained that it was important to define the workforce because of several new factors that will be affecting it in the future. "With the establishment of Micrographic Surgery and Dermatologic Oncology [MSDO] board certification that went into effect 2 years ago, potential future payor eligibility restrictions may be coming,” she said. "The adequacy of the Mohs surgery workforce is an important consideration.”

Another issue is that new board certification will be limited to fellowship-trained physicians after the first 5 years. "We wanted to compare these numbers with the fellowship numbers,” she said. "Although fellowship numbers are something that the college potentially has the power to change.”

Study Details

Ahn and colleagues used the Centers for Medicare & Medicaid Services (CMS) database to evaluate the use of the Current Procedural Terminology (CPT) code 17311, which is one of the most common billing codes for Mohs micrographic technique. Looking at data from 2015-2020, they found that there was an annual increase in the number of unique national provider identifiers (NPI) billing for 17311, at an average rate of 75.6 per year.

The total number of times that 17311 was billed also increased from 2015-2019 at an average rate of 4.7% per year but declined in 2020 by 8.4%. "Overall, there was an average of 135 new NPIs that appeared and an average of 59.4 NPIs that stopped billing for 17311," thus, an attrition rate of 59 surgeons, Ahn explained.

She emphasized that notably, the number of approved MSDO fellowship spots has remained stable since 2016 and is about 92 to 93 per year. "There are about 135 new surgeons and about two thirds are new fellowship graduates,” she said.

The researchers were also interested in seeing how saturated each surgeon was and looked at the approximate number of cases that they were handling.

Of the physicians who billed 17311 through CMS, over 26% billed less than 100 times and more than 45% billed less than 200 times, and over 80% billed less than 500 times.

"One might be able to conclude that there might be some potential flexibility depending on the future need for surgeons,” she explained.

The study was limited by several factors, one being that they only looked at CPT code 17311 and not other designated codes for Mohs surgery. Other factors such as staff and space limitations were also not accounted for since they only used billing data.

Ahn and her team are going to continue their work, and the next steps are to look at geographic trends and monitor for insurance network eligibility changes. "We are currently doing a workforce survey so we can better understand our current workforce rather than just historical data,” she concluded.

Dr Vishal Patel

Approached by Medscape Medical News for an independent comment, Vishal Patel, MD, assistant professor of dermatology and director of the cutaneous oncology program at George Washington University, Washington, DC, noted that the increase in the "billing rates of the first stage of Mohs micrographic surgery highlights not only the growing skin cancer epidemic, but also the number of providers who are providing these services.”

"This underscores the importance of standardized training guidelines and board certifications of Mohs micrographic surgeons to assure high levels of patient care and the appropriate use of Mohs micrographic surgery,” he said.

No external funding of the study was reported. Ahn reports no relevant financial relationships. Patel is a consultant for Sanofi, Regeneron, and Almirall.

American College of Mohs Surgery (ACMS) 2023 Annual Meeting. "Defining Mohs Surgery Workforce: A Cross Sectional Analysis of Centers for Medicare and MedicaidServices Current Procedural Terminology Code 17311 Billing from 2015 to 2020." Presented May 4, 2023.

Roxanne Nelson is a registered nurse and an award-winning medical writer who has written for many major news outlets and is a regular contributor to Medscape.

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