To amend title 39, United States Code, to modernize the Postal Service regulations, and for other purposes.

HR 9839 modernizes Postal Service regulations by limiting rate increases to once per year, creating sanctions for service failures that don't meet performance targets, and establishing an Office of the Customer Advocate to represent public interests. The bill requires the Postal Regulatory Commission to develop a new mail volume estimation model and makes changes to how retiree health benefits funds are invested. These provisions directly affect the Postal Service's rate-setting processes, accountability mechanisms, and customer representation. The bill aims to improve efficiency, transparency, and customer experience within the postal system.