Design and status overview of TMT telescope structure

National Astronomical Observatory of Japan (NAOJ) is responsible for procuring the Telescope Structure System (STR) of the Thirty Meter Telescope (TMT) and engaged Mitsubishi Electric Corporation (MELCO) to perform the preliminary/final design and production readiness work since 2012. The final design of the TMT STR was deemed completed through a series of external design reviews covering structural and mechanical, controls, and auxiliary systems such as the Segment Handling System (SHS), Aerial Service Platform (ASP), Elevator (ELV), safety, and the seismic isolation system. TMT STR is currently in the production readiness phase and has already passed the Production Readiness Reviews (PRRs) for major rotating mechanical structures. In this paper we present an overview of the design progress of the TMT STR, matured through extensive studies, performance assessments, and design budgets derived from bottoms-up analyses. Additionally, we discuss prototype activities to mitigate risks to performance and manufacturability of complex designs, along with the current programmatic status of the project.