With the intention of protecting its national security interests, the United States federal government established the Committee on Foreign Investment in the U.S. (CFIUS). This regime has grown to harness vast authority to block certain foreign direct investments (FDI) which it deems to be threatening to national security. Prior literature has indicated that CFIUS can potentially create deadweight loss in the economy, have negative impacts on the merger arbitrage spreads for U.S.-domiciled companies, and deter FDI with its lengthy and costly review process. Some also criticize the fact that the expansion of CFIUS’s powers has been accompanied by little oversight or transparency for the American public. What has yet to be explored with empirical analysis in existing literature, however, are the effects of CFIUS making exceptions to its mandatory filing requirements for its Five Eyes friends – the United Kingdom, Canada, Australia, and New Zealand. With an Excepted Foreign State status, investors and acquirers domiciled in one of these states are afforded advantages in the American mergers-and-acquisitions (M&A) marketplace, the value of which has yet to be quantified until now. This paper utilizes M&A data (with 238 transactions after filtering), obtained through the SDC Platinum database. Through a difference-in-difference analysis, this paper finds that U.S. companies involved in M&A transactions with an investor domiciled in a CFIUS-excepted state experience an estimated 4.59% higher cumulative abnormal stock return post-announcement. However, there is enough uncertainty in this estimate that we cannot reject the null hypothesis of no effect at standard levels of statistical significance. In any case, it is possible that the CFIUS review process makes investors doubtful of a merger or acquisition being completed.