The format of the UPSC Civil Services Main Examination consists of nine papers, including compulsory and optional subjects. The compulsory papers include **Essay**, **General Studies I-IV** covering various domains such as social issues, governance, and security, along with the **Indian Language** and **English** papers. Candidates choose one optional subject from a predefined list for two papers. This structure evaluates a candidate’s comprehensive knowledge and analytical skills across multiple subjects while assessing communication and writing abilities.