The STEM RESTART Act proposes to amend the Workforce Innovation and Opportunity Act by creating a new national program designed to help mid-career workers reenter or transition into the STEM workforce. The primary mechanism for this program is the provision of competitive grants to eligible small-sized and medium-sized STEM businesses . These grants are intended to fund high-quality, paid returnships or internships that lead to positions above entry level, with competitive salaries and benefits, and provide clear pathways for career advancement. The program specifically targets unemployed or underemployed individuals, with a particular focus on workers from rural areas. Grants will be awarded for initial periods of 3 to 5 years, with annual payments ranging from $100,000 to $1,000,000 for small enterprises and $500,000 to $5,000,000 for medium enterprises or consortia. Eligible entities must be U.S.-based, not in bankruptcy, and operate within in-demand STEM fields, and they may partner with educational institutions or service providers for training. Grant funds can cover participant education, training, compensation, and support for existing employees mentoring participants, with an annual authorization of $50,000,000 for fiscal years 2026 through 2030.