Creates the Transparency in Downcoding Act. Provides that the Act applies to certain policies of health insurance amended, delivered, issued, or renewed on or after the effective date of the Act, except for employee or employer self-insured health benefit plans under the federal Employee Retirement Income Security Act of 1974 and health care provided pursuant to the Workers' Compensation Act or the Workers' Occupational Diseases Act. Prohibits a health insurance issuer from using an automated process, system, or tool to downcode a claim; from downcoding a claim based solely on the reported diagnosis codes; and from using downcoding practices in a targeted or discriminatory manner against physicians who routinely treat patients with complex or chronic conditions. Requires downcoding decisions to be made by a physician licensed to practice medicine in all its branches in any United States jurisdiction and of the same or similar specialty as a physician who typically manages the medical condition or disease. Sets forth provisions concerning notification requirements for downcoded claims; the appeal process for downcoded claims; enforcement by the Department of Insurance; and penalties. Provides that any pattern or practice of discriminatory downcoding identified by the Director of Insurance or another regulatory authority shall be subject to enforcement actions, including fines, restitution, or suspension of the health insurance issuer's license in this State. Effective immediately.