A new study suggests "upcoding" practices are growing across outpatient service lines.
The report, compiled by researchers at Trilliant Health, found that the share of visits that were coded at higher intensities grew in emergency care, urgent care and physician office visits between 2018 and 2023. For example, the number of emergency department visits coded as 99284, or level four of five total, grew from 32.5% to 39.6% in the study window.
Providers use standard CPT codes for outpatient visits, ranging from level one to level five, to indicate the intensity of services offered and the amount of time clinicians spent with a patient.
The study similarly found an increase in urgent care visits coded at level four, with the share growing from 34% to 40.6% between 2018 and 2023. For physician office visits, the share of those coded at level four increased from 38.5% to 45%.
In tandem, the study found a decline in the number of patient visits coded at lower intensity. For urgent care, the share of visits coded at level one decreased from 9.5% to 2.9% by 2023.
"Clinical coding of ambulatory care has significantly changed over recent years in parallel with increased utilization of ambulatory care sites," the Trilliant researchers wrote. "The way in which this trend impacts nearly every diagnosis category suggests that it is not isolated to specific clinical areas but instead reflects a broader evolution in healthcare delivery and administration."
The study also breaks down coding trends in specific conditions and disease states. For emergency care, for example, some of the largest increases in coding intensity were seen for diseases of the ear and mastoid process (27.9% to 46.9%); diseases of the eye and adnexa (28.1% to 46.7%); and skin and subcutaneous tissue conditions (38.6% to 54.6%).
Within those broader categories, the study found that the largest percentage point increase in the share of high intensity coding was for rashes and "other nonspecific skin eruptions," which grew by 19.7 percentage points between 2018 and 2023.
In urgent care, the largest increases were among diseases of the blood, which saw the share of visits coded as high intensity increase from 42.7% to 61.6%. Diseases of the circulatory system also saw a notable intensity increase, rising from 40.5% to 59.4%.
The researchers said these trends may point toward more patients presenting with higher acuity needs, but it's more likely a change in administrative behavior. For instance, some documentation templates may encourage providers to do more detailed coding, and there are incentives to optimize revenue cycle strategies to increase reimbursement.
For payers, trends like this can make it even harder for them to get their arms around rising healthcare costs. In response, they're turning up the heat on utilization management and other strategies to mitigate costs, which "can erode trust and reinforce the opacity of healthcare pricing," the researchers said.
"As these dynamics play out, pressure is mounting to revisit the alignment between clinical complexity and billing levels," the researchers wrote. "Without meaningful changes, increasing coding intensity for ambulatory care is likely to continue, driven as much by documentation strategy as by clinical necessity."