The discussion of emission performance test method repeatability has been a long-standing problem. In March of 2016 the U.S. EPA released a discussion paper on processes for developing improved cordwood test methods for wood heaters. This paper discussed the need to improve repeatability of cordwood fueling protocols and emission measurements to improve confidence in certification processes; however, repeatability for pellet stoves was not addressed. In 2016 the Alliance for Green Heat held the Pellet Stove Design Challenge which was created to test, study, and assess high-efficiency, low-emission pellet stoves. During this workshop, three pellet stoves were selected for extensive testing which provided results on their repeatability to one single test method in the U.S. in terms of emission rates, emission indices, and efficiency. The goal of this study was to assess the repeatability of a single certification test method for pellet stoves and the emission data used for certification purposes. Overall, the repeatability of the test method was favorable with variation in the overall burn rate (kg/h) of 4%, 2%, and 3% for stoves 1, 2, and 3, respectively. The variability in emission rate (g/h) for stoves 1, 2, and 3 was 4%, 17%, and 65%, respectively, which raised concerns for regulatory purposes. However, the concern was met with suggestions for test method development which may include sampling during higher emission periods such as start-up or burn out, sampling at higher flow rates, and moving toward higher resolution scales. Specifically, including start-up or burn out periods which are typically "poorer combustion periods" is more reflective of in-field use and a better measure of the actual stove's performance. This work also provided support for EPA's New Source Performance Standard requirement for manufacturers to report CO emissions and efficiency.