Equity indexed annuities are regulated by state insurance departments in the United States. Each state has its own insurance department that is responsible for overseeing insurance products, including annuities. These departments ensure that insurance companies comply with state laws and regulations to protect consumers. The regulations may vary from state to state, so it's important to check with the specific state insurance department for detailed information on the regulation of equity indexed annuities in a particular state. Additionally, the National Association of Insurance Commissioners (NAIC) provides guidance and model regulations for insurance departments to follow. The NAIC is a voluntary organization of state insurance regulators that promotes uniformity and consistency in insurance regulation across the United States. While the NAIC does not have direct regulatory authority, its model regulations and guidelines often influence state insurance laws and regulations. Therefore, the NAIC's work can indirectly impact the regulation of equity indexed annuities. It's worth noting that the regulation of equity indexed annuities may also involve other federal regulatory bodies, such as the Securities and Exchange Commission (SEC) and the Financial Industry Regulatory Authority (FINRA), depending on the specific features and marketing of the annuity product. However, the primary responsibility for regulating equity indexed annuities lies with the state insurance departments.