This document is about an analysis of anomalies in Form 5500 filings that were used to determine the funding mechanism of employer-provided group health plans. The authors collected supplemental data from a sample of filers to understand the sources of these anomalies and improve the algorithm used to infer funding mechanism from the Form 5500 data. The report discusses common explanations for the observed anomalies and suggests potential improvements to the Form 5500 filing process to reduce such issues in the future.