CMS audits claims on an annual basis to identify improper payments. These improper payments do not measure fraud. Rather, they estimate the share of payments that did not meet Medicare coverage, coding, and billing rules. In the most recent Improper Payment Report by specialty, chiropractic has the highest Part B improper payment rate, clocking in at 37.3% of claims. While this is an improvement from 41% in 2018, there is still significant room for improvement. As recently as 2016, the improper payment rate was 46%. 

Insufficient documentation remains the primary reason for improper payments, comprising 95.8% of errors. A lack of medical necessity (2.7%) and incorrect coding (1.5%) round out the remainder. A careful review of Chapter 4 — Documentation in the 2021 ChiroCode DeskBook can provide guidance on how to properly document services provided.