UPSC CDS Exam Guide — Eligibility, Pattern, Syllabus & Preparation Tips

The Combined Defence Services (CDS) exam is conducted by UPSC twice a year to recruit officers for the Indian Military Academy (IMA), Indian Naval Academy (INA), Air Force Academy (AFA), and Officers' Training Academy (OTA). It is one of the most prestigious defence entrance exams in India.

This guide covers everything you need to know about the CDS exam — eligibility, exam pattern, syllabus, application process, and preparation strategy.

What Is the CDS Exam?

CDS stands for Combined Defence Services Examination. UPSC conducts it to select candidates for training at:

• IMA (Indian Military Academy) — Dehradun
• INA (Indian Naval Academy) — Ezhimala, Kerala
• AFA (Air Force Academy) — Dundigal, Hyderabad
• OTA (Officers' Training Academy) — Chennai

After clearing the written exam and SSB interview, selected candidates join these academies for training and are commissioned as officers in the Indian Armed Forces.

CDS Exam Eligibility Criteria

Nationality

• Must be a citizen of India
• Subjects of Nepal or Bhutan, Tibetan refugees who came to India before 1 January 1962, or persons of Indian origin migrated from specified countries are also eligible

Age Limit

Educational Qualification

Physical Standards

Candidates must meet physical and medical standards as prescribed by the armed forces. This includes height, weight, eyesight, and general fitness requirements. Detailed standards are available in the official notification.

CDS Exam Pattern

The CDS written exam consists of objective-type questions. The pattern differs for IMA/INA/AFA and OTA.

For IMA, INA, and AFA

For OTA

Note: There is negative marking — one-third of marks allotted to a question are deducted for each wrong answer.

SSB Interview

Candidates who clear the written exam are called for a 5-day SSB (Services Selection Board) interview, which carries 300 marks for IMA/INA/AFA and 200 marks for OTA. The SSB tests:

• Intelligence and personality
• Group tasks and discussions
• Personal interview
• Conference

CDS Syllabus Overview

English

• Comprehension passages
• Spotting errors
• Sentence arrangement
• Synonyms and antonyms
• Fill in the blanks
• Idioms and phrases
• Sentence improvement

General Knowledge

• Current affairs (national and international)
• Indian history and freedom movement
• Indian polity and constitution
• Indian economy
• Geography of India and the world
• General science (Physics, Chemistry, Biology)
• Defence-related news

Elementary Mathematics (IMA/INA/AFA only)

• Number system, HCF, LCM
• Algebra (basic operations, quadratic equations)
• Trigonometry
• Geometry (lines, triangles, circles)
• Mensuration (area, volume)
• Statistics (mean, median, mode)
• Profit and loss, percentages

How to Apply for CDS Exam

1. Check notification: UPSC publishes CDS notifications in October/November (CDS I) and May/June (CDS II) in the Employment News and on the UPSC website
2. Register: Create an account on upsconline.nic.in if you don't have one
3. Fill application: Complete the online form with personal, educational, and preference details
4. Upload documents: Photograph and signature as per specifications
5. Pay fee: Pay the application fee online
6. Submit: Review and submit the application. Download the confirmation page

Application Fee

• General/OBC: ₹200
• SC/ST/Women: Exempted
• Payment modes: Net banking, UPI, or any online method via the UPSC portal

Important Dates Pattern

CDS exam is conducted twice a year:

Always check the official UPSC website for exact dates.

Preparation Tips

1. Know the Syllabus Thoroughly

Start by reading the official syllabus. CDS covers basic-level topics, so depth matters less than breadth and accuracy.

2. Focus on English

English carries significant weight. Read newspapers daily, practice comprehension passages, and revise grammar rules. Recommended resources:

• Wren & Martin (grammar)
• The Hindu or Indian Express (reading practice)

3. Build GK Through Current Affairs

Read a quality newspaper daily and maintain monthly notes. Cover static GK topics like Indian history, polity, and geography alongside current affairs.

4. Practice Mathematics Regularly

For IMA/INA/AFA candidates, maths is crucial. Solve previous years' papers and focus on speed and accuracy. The level is roughly Class 10–12 standard.

5. Solve Previous Years' Papers

CDS papers from the last 10 years give you an excellent idea of the question pattern, difficulty level, and frequently tested topics.

6. Time Management

With 120 questions in 2 hours, you have about 1 minute per question. Practice with a timer to build speed.

7. Prepare for SSB Early

Don't wait until you clear the written exam. Start reading about SSB procedures, personality tests, and group tasks early.

CDS vs Other Defence Exams

Related guides:

• UPSC NDA Exam Guide — for candidates who want to join defence after 10+2
• Banking Exam Preparation Guide — for those exploring other government career options

Frequently Asked Questions

1. How many times is CDS exam conducted in a year?

CDS is conducted twice a year — CDS I (usually in February–April) and CDS II (usually in September–November).

2. Can women apply for CDS exam?

Yes, women can apply for OTA (Officers' Training Academy). IMA, INA, and AFA entries are for men only through CDS.

3. Is there negative marking in CDS?

Yes, one-third of the marks assigned to a question are deducted for each wrong answer.

4. What is the age limit for CDS exam?

For IMA, INA, and AFA: 19–24 years. For OTA: 19–25 years. Age relaxation may apply for certain categories.

5. Can final-year students apply for CDS?

Yes, candidates appearing in the final year of their degree can apply, provided they have the degree by the time of joining the academy.

6. What happens after clearing CDS written exam?

Candidates who qualify the written exam are called for SSB interview. Those who clear both are allotted training academies based on merit and preference.

7. Is CDS exam tough?

The written exam is of moderate difficulty (Class 10–12 level for maths, graduation level for English and GK). The SSB interview is considered more challenging and has a lower selection rate.

This guide is for informational purposes. Always refer to the official UPSC website for the latest notifications, eligibility criteria, and exam dates.