HB 3999 creates a statutory process for the transfer and novation of insurance policies between insurers through an insurance business transfer plan. It establishes a legal framework that allows an insurer to transfer policies and associated obligations to another insurer, subject to approval by the Texas Department of Insurance (TDI) and a district court. The bill defines key terms such as "transferring insurer," "assuming insurer," and "policyholder," while outlining the required elements of an insurance business transfer plan, including financial assessments, independent expert reports, policyholder notifications, and court review. The commissioner of insurance must review and approve the transfer before it can be submitted for judicial approval. Once approved by the court, the assuming insurer becomes the direct insurer of the transferred policies, and the transferring insurer is released from liability. The bill also imposes fees for application filings and independent expert reviews, with funds directed to the Texas Department of Insurance operating account.