https://techcrunch.com/2021/11/30/nasa-details-intent-to-replace-the-international-space-station-with-a-commercial-space-station-by-2030/

NASA’s auditing body, the Office of Audits, has produced a report detailing the agency’s commitment to replacing the International Space Station (ISS) with one or more commercial space stations once the orbiting lab is retired — an event scheduled for 2024 right now, but all indications are that the ISS’s operational life will be extended to 2030, which is when the agency is assuming it’ll be able to hand off human occupation of an on-orbit science facility to a private company.

This audit basically details the current costs of maintenance and operation of the ISS, and also explains why it thinks that there will still be an essential need for a research facility that can provide a test bed for prolonged human exposure to space, as well as for development and demonstration of tech key to helping people explore deep space, including the establishment of a more permanent presence on the Moon and exploration of Mars.