The Florida workers’ compensation system uses the 1996 Florida Uniform Permanent Impairment Rating Schedule (FUPIRS), that was based in part on the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Third Revised and Fourth Editions (the latter published in 1993). The authors ask if changes in the AMA Guides resulted in different impairment ratings and different awards. To these ends, the authors examined seventy-five cases that were randomly selected from a cohort of two hundred cases that was studied previously [see The Guides Newsletter, January/February 2010]. The average whole person impairment (WPI) per case was 5.3% WPI according to FUPIRS; 5.3% WPI according to the AMA Guides, Fourth Edition; 5.8% WPI according to the fifth edition; and 4.6% WPI according to the sixth edition. The difference between the WPIs was tested using a paired sample t test (alpha = .05), and results showed that the difference in WPI between FUPIRS and the sixth edition (0.7% WPI) was not statistically significant. The authors acknowledge that the limited range of impairment values in this study may have contributed to the lack of statistical significance when group means are compared because 84% of the cases were rated 10% WPI or less. The authors call for an expanded study to determine if meaningful differences exist between rating methodologies in a more diverse, less skewed sample.