Compulsory Subjects for UPSC Prelims and Mains 2026

The compulsory subjects for the UPSC exam include history, geography, polity, and economy for prelims. The Mains stage requires seven merit-ranking papers (an essay, 4 GS papers, and 2 optional papers) and two qualifying language papers. To be on the final merit list, all candidates must pass these tests.

Check Out: UPSC Exam Preparation Books 2026

Compulsory Subjects for UPSC Exam In Prelims

The preliminary stage is a screening test. If you do not clear the compulsory subjects for UPSC exam prelims, your journey ends there for the year.

 Important Topics Covered in GS Paper I 

This is the merit-ranking paper for Prelims. It includes:

• History of India and the Indian National Movement.

• Indian and world geography (physical, social, and economic).

• Indian Polity and Governance (Constitution, Panchayati Raj).

• Economic and Social Development (Poverty, Inclusion).

• General Science and Environment.

Important Topics Covered Civil Services Aptitude Test (CSAT)

The CSAT, or General Studies Paper II tests your reasoning and analytical skills. It covers:

• Comprehension and interpersonal skills.

• Logical reasoning and analytical ability.

• Basic numeracy (Class X level).

• Data interpretation (charts, graphs, tables).

Check Out: PW UPSC Modules

UPSC Prelims Papers Marks And Weightage

Marks, Qualifying Criteria, and Negative Marking

Both prelims papers are worth 200 marks each. A crucial point to remember is the negative marking of 1/3rd (0.66 marks for GS-I and 0.83 for CSAT) for every wrong answer.

Role of CSAT in Prelims Qualification

While GS Paper I determines your cut-off, the CSAT serves as a qualifying paper. You must score at least 33% (66 marks out of 200) to have your GS Paper I evaluated.

Compulsory Subjects for UPSC Exam In Mains

The Mains stage is where the "real" competition begins. Success in compulsory subjects for the UPSC exam mains requires deep analytical writing.

Structure of the UPSC Mains Examination

Mains consists of 9 descriptive papers. Each paper lasts 3 hours. Seven of these papers are used to calculate your final merit rank, while two are qualifying.

 UPSC Mains Essay Paper

Candidates must write two essays from a choice of topics. This paper tests your ability to organise ideas and write effectively about social, political, or philosophical issues.

General Studies Paper I 

This paper covers Indian heritage and culture, world history, and the salient features of Indian society and world geography.

General Studies Paper II 

This paper focuses on the Indian Constitution, governance, social justice, and India's relations with neighbours and global powers.

General Studies Paper III 

This is a highly dynamic paper covering economic development, biodiversity, disaster management, and internal security challenges.

General Studies Paper IV 

This paper assesses the candidate's attitude and approach to issues relating to integrity and probity in public life.

Check Out: UPSC Previous Year Papers

Compulsory Language Papers in UPSC Mains

These are "gatekeeper" papers. If you fail these, your GS and essay papers will not even be checked.

Qualifying Indian Language Paper 

Candidates choose one language from the Eighth Schedule of the Constitution. It tests translation, precise writing, and grammar.

Qualifying English Language Paper 

The English Language Paper (Qualifying) is a mandatory paper that assesses all subjects required for the UPSC exam in English. It includes comprehension, essay writing, and basic vocabulary.

Importance of Language Papers in the Final Selection

Both papers are worth 300 marks each. You must score 25% (75 marks) to qualify. While these marks aren't added to the merit list, failing them leads to immediate disqualification.

Check out: UPSC Revision Books

Optional Subject Papers in UPSC Mains

Optional subjects are based on choice. The commission does not fix the subject itself, even though the papers are an essential part of the exam process.

Popular Optional Subjects Chosen by Candidates

• Political Science and International Relations (PSIR)

• Geography and History

• Sociology and Public Administration

• Literature (Hindi, English, etc.)

Difference Between Compulsory and Optional Subjects

While compulsory subjects for the UPSC exam are fixed for all, the "Optional Subject" allows candidates to choose one discipline from a list of 48 subjects (like sociology, history, or anthropology). Compulsory subjects focus on general awareness and foundational knowledge, whereas optional subjects test specialised expertise in a particular field.

 Compulsory Papers at Each Stage of the UPSC Exam

The 2026 examination is divided into three levels:

1. Prelims: Objective type, featuring two compulsory papers.

2. Mains: Descriptive type, consisting of nine papers (all mandatory to attend).

3. Personality Test: An interview to assess the candidate's character and mental alertness.

Check Out: UPSC Question Banks

Preparation Strategy for Compulsory Subjects for UPSC Exam

Preparation for Prelims and Mains Together

Most subjects, such as politics, history, and economics, intersect. It is smart to study these with a "mains-first" approach to build deep concepts. This makes it much easier to answer prelims MCQs.

Importance of Current Affairs in All Compulsory Papers

Current Affairs is the thread that ties the syllabus together, whether it's GS Paper III in Mains or GS Paper I in Prelims. It is important to read a daily newspaper like The Hindu.

Recommended Resources

• NCERTs (Class 6-12): The foundation for all compulsory subjects.

• Standard Books: Laxmikanth for Polity, Spectrum for Modern History.

• Practice: Regular mock tests for Prelims and daily answer writing for Mains.

Read More: UPSC Optional Subject List

Compulsory Subjects for UPSC Exam FAQ

What are the compulsory subjects for UPSC exam?

In Prelims, there are 2 papers (GS and CSAT). In Mains, there are 9 papers, including 4 General Studies papers, 1 essay, 2 language papers, and 2 optional papers.

Is CSAT a qualifying paper for the 2026 exam?

Yes, CSAT remains a qualifying paper where you need to score 33% (66 marks) to pass.

Can I choose any language for the Indian Language paper?

You can choose any language listed in the Eighth Schedule of the Indian Constitution, such as Hindi, Tamil, Bengali, or Marathi.

What is the minimum qualifying mark for the English paper?

Candidates must score at least 25% (75 out of 300 marks) in the compulsory English paper.

Are marks of the language papers counted for the final rank?

No, the marks for Paper A (Indian Language) and Paper B (English) are only qualifying and are not added to the final merit score.