University of Kentucky Center of Tobacco Reference Products (CTRP) has provided reference cigarettes for almost 50 years. These reference cigarettes are widely used in tobacco research including analytical method development and modified risk tobacco product development. In 2014, CTRP obtained a service agreement with the U.S. Food and Drug Administration (FDA) to produce a certified reference cigarette. The first certified reference cigarette, 1R6F, was manufactured in March, 2015. However, there are no data showing the stability of 1R6F during long-term storage. The objective of this project is to study the stability of the cigarette tobacco filler and resulting smoke of 1R6F. Cigarettes were stored at -20 °C, 4 °C and room temperature (~22 °C) for 1, 2, 3, 6, 9 and 12 months. Before they were analyzed, cigarettes were transferred out stepwise from these storage conditions until they reached room temperature. Cigarettes stored in -20 °C were transferred to 4 °C for 24 hr then moved to room temperature for at least 2 hr. The sampled cigarettes were conditioned for 48 hr at 22 °C and 60 % relative humidity prior to smoking and filler analysis for selected constituents. Filler analysis included oven volatiles, individual alkaloids and TSNAs. Smoke analysis included the measurement of individual alkaloids, TSNAs, CO and TPM under ISO smoking regime. There were no significant changes for the oven volatiles, nicotine and NNN in the filler from 4 °C or -20 °C conditions. However, oven volatiles decreased significantly when cigarettes were stored at room temperature. There were no significant changes for puff/cigarette, CO, TPM, alkaloids and TSNAs in the smoke of cigarettes under -20 °C, 4 °C and room temperature conditions. Our experimental data demonstrated 1R6F cigarettes were relatively stable after one year storage at 4 °C or -20 °C for selected constituents. This study will continue for the duration of the 1R6F cigarette supply.