The Tax Cuts and Jobs Act of 2017 leaves many promises of tax reform unfulfilled. In this paper, we examine the plan’s prospects to boost future growth, and discuss fundamental reforms that would boost the stock of capital and generate sustained, long-term growth. After making the case that the current tax code is unsustainable and that reform will be revisited, we recommend a series of strategies for future Congresses, including limiting windfall tax breaks on already-committed capital, providing targeted tax cuts on wages to boost labor supply, reducing the most harmful tax distortions, and administering the tax code more effectively.