Purpose: This study examines the impact of the US government customer concentration and product innovation in supplier firms. The US government customer concentration is defined as the proportion of sales made by a supplier firm to the US government as a major customer. To measure product innovation, the author uses two key metrics: the number of patents and the novelty of the patents. The results indicate that a supplier firm's relationship with the US government, as measured by the tenure of the relationship, has a significant impact on product innovation. Furthermore, the author shows that changes in the composition of the US government, Senate can also affect the level of innovation in supplier firms. Design/methodology/approach: This study employs the Compustat's Segment Customer database and the National Bureau of Economic Research (NBER) Patent Citation database to gather information regarding patents granted by the United States Patent and Trademark Office (USPTO). The author also incorporates data from US Congressional committees from the 96th to 115th Congresses to assess the effect of changes in seniority of US senators on influential committees on the firm's innovation. For a robustness test, the author utilizes a propensity score matched analysis. Findings: The author demonstrates that a firm's dependence on the US government as a customer channel for an extended period negatively impacts the firm's innovation efficiency, as measured by the number of patents, citations and novelty of the patents. In addition, the author provides evidence that changes in the seniority of US senators on influential committees have a significant impact on firms located in the same state as the new senior senators. These firms decrease innovative efforts due to the political connections, resulting in lower levels of innovation. These findings are robust after controlling the endogeneity issues. In conclusion, this study contributes to the existing literature by offering insight into the relationship between customer concentration and firm innovation. The findings highlight the importance of considering the relationship between firms and their customer base in determining innovation outcomes. Originality/value: This study demonstrates that a heavy reliance on the US government as a customer channel has a detrimental impact on a firm's innovation efficiency. Furthermore, the author analyzes the exogenous shock of changes in the seniority of US senators on the relationship between customer dependence and innovation. By utilizing a propensity matched sample, the author addresses endogeneity concerns and provides robust evidence for empirical findings. In conclusion, this study sheds light on the complex relationship between customer dependence and firm innovation, particularly in the context of the US government as a sales channel. [ABSTRACT FROM AUTHOR]