🪖 UPSC Defence Examination

Combined Defence Services (CDS)

Complete CDS guidance — eligibility, IMA, INA, AFA, OTA, subjects, books, NCERT, exam pattern, SSB, medical and preparation strategy.

What is CDS?

The Combined Defence Services (CDS) Examination is conducted by UPSC for admission to officer-training academies of the Indian Armed Forces. The main entries covered through CDS are the Indian Military Academy (IMA), Indian Naval Academy (INA), Air Force Academy (AFA) and Officers' Training Academy (OTA), subject to the applicable notification.

UPSC conducts CDS twice a year. The UPSC 2026 examination archive lists CDS (I), 2026 and CDS (II), 2026; CDS (II), 2026 was notified on 20 May 2026 and is scheduled for 13 September 2026. citeturn0search0turn0search1

CDS Entries / Academies

01

IMA

Indian Military Academy — Permanent Commission entry for eligible male candidates as specified in the notification.

02

INA

Indian Naval Academy — Permanent Commission entry for eligible candidates with the required educational qualification.

03

AFA

Air Force Academy — Flying/other applicable entry as specified in the notification.

04

OTA

Officers' Training Academy — Short Service Commission entry for eligible candidates.

CDS Eligibility

Academy Educational Qualification
IMA Degree from a recognised university or equivalent.
INA Degree in Engineering from a recognised university/institution.
AFA Degree from a recognised university with Physics and Mathematics at 10+2 level, or Bachelor of Engineering, subject to notification conditions.
OTA Degree from a recognised university or equivalent.

Candidates appearing in the final year/semester of the qualifying degree may be eligible subject to the conditions in the relevant UPSC notification. Exact age, gender, marital-status and other conditions vary by academy and notification. citeturn0search19

CDS Written Exam Pattern

Academy Paper Marks Duration
IMA English + General Knowledge + Elementary Mathematics 300 6 Hours total
INA English + General Knowledge + Elementary Mathematics 300 6 Hours total
AFA English + General Knowledge + Elementary Mathematics 300 6 Hours total
OTA English + General Knowledge 200 4 Hours total

For IMA, INA and AFA, each of the three papers carries 100 marks and has a 2-hour duration. For OTA, English and General Knowledge are each 100 marks with 2 hours per paper. citeturn0search19

CDS Subjects

Subject What to Study
English Grammar, vocabulary, sentence usage, comprehension, synonyms, antonyms and basic language skills
General Knowledge Current affairs, History, Geography, Polity, Economy, General Science and defence-related awareness
Elementary Mathematics Arithmetic, Algebra, Trigonometry, Geometry, Mensuration and Statistics

OTA candidates do not have the Elementary Mathematics paper in the written examination. UPSC's official previous-paper archive lists English, General Knowledge and Elementary Mathematics papers for CDS. citeturn0search2

English — Important Topics

  • Parts of Speech
  • Subject-Verb Agreement
  • Tenses and Articles
  • Prepositions and Conjunctions
  • Active and Passive Voice
  • Direct and Indirect Speech
  • Vocabulary, Synonyms and Antonyms
  • Sentence Improvement and Error Detection
  • Reading Comprehension

General Knowledge — Important Topics

Area Main Topics
History Ancient, Medieval and Modern India, Freedom Movement and important events
Geography Physical geography, India, climate, rivers, resources, agriculture and world geography basics
Polity Constitution, Parliament, President, Supreme Court, fundamental rights, duties and governance
Economy Basic economic concepts, banking, inflation, budget and major economic developments
Science Physics, Chemistry, Biology and everyday science
Current Affairs National and international events, defence, awards, sports, science and important appointments

Elementary Mathematics — Important Topics

Topic Preparation Focus
Arithmetic Number system, HCF/LCM, percentages, ratio, average, profit & loss, simple/compound interest, time & work, time & distance
Algebra Basic identities, polynomials, quadratic equations, simultaneous equations and elementary functions
Geometry Lines, angles, triangles, circles and basic theorems
Mensuration Areas and volumes of common figures
Trigonometry Ratios, identities, heights and distances
Statistics Collection and representation of data, averages and basic statistics

Recommended Books — Subject Wise

Subject Books / Material Purpose
English NCERT English + Wren & Martin / standard grammar reference + CDS PYQs Grammar, vocabulary and comprehension
General Knowledge NCERT 6–12 + Lucent's General Knowledge + newspaper/current-affairs notes + CDS PYQs Foundation and revision
Mathematics NCERT Mathematics 6–10 + standard CDS Mathematics guide + PYQs Concepts and practice
History NCERT History + Lucent GK / standard reference + PYQs Static GK
Geography NCERT Geography 6–10/12 + Atlas + PYQs Concepts and maps
Polity NCERT Political Science + standard Indian Polity reference Constitution and governance
Current Affairs Reliable newspaper/current-affairs source + monthly notes Recent events
Previous Year Papers Official UPSC CDS question papers Actual exam practice

NCERT Books for CDS

Subject Useful Classes Priority
History 6–12 Very Important
Geography 6–12 Very Important
Political Science 6–12 Important
Science 6–10 Important
Mathematics 6–10 Very Important for basic foundation
English School-level textbooks Useful for language foundation

NCERT is a foundation resource, not the complete CDS preparation. Combine it with the official syllabus, PYQs, current affairs and mock tests.

Selection Process

01

Written Exam

UPSC written examination according to the selected academy.

02

SSB Interview

Successful written candidates are called for the Services Selection Board process as applicable.

03

SSB Assessment

Intelligence/personality assessment, group tasks and interview as prescribed.

04

Medical

Prescribed service medical examination.

05

Final Merit

Final selection depends on applicable written/SSB performance, vacancies and eligibility.

06

Training

Selected candidates join the relevant academy for training.

SSB Preparation

🗣️

Communication

Practise clear communication, listening and structured expression.

🧠

Reasoning

Develop logical thinking and problem-solving ability.

👥

Teamwork

Build cooperation, leadership and responsible group behaviour.

🏃

Fitness

Maintain regular running, strength, mobility and general fitness.

📰

Awareness

Follow national, international and defence-related current affairs.

🎯

Confidence

Prepare honestly and consistently for interview and assessment.

Documents Required

  • Matriculation / 10th certificate for date-of-birth proof as prescribed
  • Degree / provisional degree and marksheets as applicable
  • Valid photo identity details
  • Category certificate, if applicable
  • Other documents requested by UPSC or SSB during later stages

CDS Application Process

01

Notification

Read the latest CDS notification carefully.

02

Registration

Complete the required UPSC online registration.

03

Application

Enter personal, educational and academy preference details correctly.

04

Fee

Pay the applicable fee where required.

05

Admit Card

Download the e-Admit Card from the official UPSC portal.

06

Exam

Appear for the written examination at the allotted centre.

Preparation Strategy

📚

NCERT Foundation

Complete relevant NCERT books and make short revision notes.

📝

PYQs

Solve official CDS papers topic-wise and as full tests. UPSC publishes English, GK and Elementary Mathematics papers. citeturn0search2

📰

Current Affairs

Revise national, international, defence, sports, science and awards news.

Maths Practice

Practise arithmetic and other syllabus topics regularly if applying for IMA, INA or AFA.

⏱️

Mock Tests

Practise with the actual paper time limits and analyse mistakes.

🏃

Fitness + SSB

Prepare fitness, communication and personality skills alongside academics.

Official UPSC Resources

UPSC Official Websiteupsc.gov.in ↗
CDS NotificationsExam Notifications ↗
Previous Year PapersUPSC Question Papers ↗
Online Applicationupsconline.nic.in ↗

Important Note

Age, date-of-birth window, gender, marital status, qualification, vacancies, fee and medical standards can change between CDS notifications. Always use the latest UPSC notification as the final authority. citeturn0search0turn0search19

CDS क्या है?

Combined Defence Services (CDS) Examination का आयोजन UPSC द्वारा Indian Military Academy (IMA), Indian Naval Academy (INA), Air Force Academy (AFA) और Officers' Training Academy (OTA) में officer training के लिए admission हेतु किया जाता है।

UPSC CDS examination साल में दो बार आयोजित करता है। 2026 में CDS (I) और CDS (II) दोनों examinations listed हैं। CDS (II), 2026 की notification 20 May 2026 को जारी हुई और परीक्षा 13 September 2026 के लिए निर्धारित है। citeturn0search0turn0search1

CDS Entries / Academies

01

IMA

Indian Military Academy — notification के अनुसार eligible candidates के लिए Permanent Commission entry।

02

INA

Indian Naval Academy — required educational qualification वाले eligible candidates के लिए entry।

03

AFA

Air Force Academy — notification में दी गई applicable entry के अनुसार।

04

OTA

Officers' Training Academy — Short Service Commission entry।

CDS Eligibility

Academy Educational Qualification
IMA Recognised university से Degree या equivalent qualification।
INA Recognised university/institution से Engineering Degree।
AFA Recognised university से Degree जिसमें 10+2 level पर Physics और Mathematics हो, या Bachelor of Engineering; notification की conditions लागू होंगी।
OTA Recognised university से Degree या equivalent qualification।

Final-year/semester candidates भी notification की conditions के अनुसार eligible हो सकते हैं। Exact age, gender, marital status और अन्य conditions latest UPSC notification से check करें। citeturn0search19

CDS Exam Pattern

Academy Subjects Total Marks Total Time
IMA English + General Knowledge + Elementary Mathematics 300 6 Hours
INA English + General Knowledge + Elementary Mathematics 300 6 Hours
AFA English + General Knowledge + Elementary Mathematics 300 6 Hours
OTA English + General Knowledge 200 4 Hours

IMA, INA और AFA में तीनों papers 100-100 marks के हैं और प्रत्येक की duration 2 hours है। OTA में English और General Knowledge 100-100 marks के हैं। citeturn0search19

CDS Subjects

Subject मुख्य Topics
English Grammar, Vocabulary, Sentence Usage, Comprehension, Synonyms और Antonyms
General Knowledge Current Affairs, History, Geography, Polity, Economy, General Science और Defence Awareness
Elementary Mathematics Arithmetic, Algebra, Trigonometry, Geometry, Mensuration और Statistics

OTA के written examination में Elementary Mathematics paper नहीं होता। UPSC की official previous-paper list में CDS के English, General Knowledge और Elementary Mathematics papers उपलब्ध हैं। citeturn0search2

Subject-wise Books

Subject Books / Material
English NCERT English + Wren & Martin / standard grammar reference + CDS PYQs
General Knowledge NCERT 6–12 + Lucent GK + current-affairs notes + CDS PYQs
Mathematics NCERT Mathematics 6–10 + standard CDS Mathematics guide + PYQs
History NCERT History + Lucent GK / standard reference + PYQs
Geography NCERT Geography 6–10/12 + Atlas + PYQs
Polity NCERT Political Science + standard Indian Polity reference
Current Affairs Reliable newspaper/current-affairs source + monthly revision notes

NCERT Books

Subject Classes Priority
History 6–12 Very Important
Geography 6–12 Very Important
Political Science 6–12 Important
Science 6–10 Important
Mathematics 6–10 Very Important for foundation

Selection Process

01

Written Exam

Academy के अनुसार UPSC written examination।

02

SSB Interview

Written exam qualify करने वाले candidates के लिए applicable SSB process।

03

Assessment

Intelligence/personality assessment, group tasks और interview।

04

Medical

Prescribed service medical examination।

05

Final Merit

Performance, vacancies और eligibility के आधार पर final selection।

06

Training

Selected candidates संबंधित academy में training लेते हैं।

Preparation Strategy

📚

NCERT

Relevant NCERT books से foundation मजबूत करें।

📝

PYQs

Official CDS papers को topic-wise और full-length solve करें।

📰

Current Affairs

National, international, defence, sports और science news पढ़ें।

Maths

IMA, INA और AFA के लिए Mathematics की नियमित practice करें।

⏱️

Mock Tests

Actual time limit के साथ mock tests दें और mistakes analyse करें।

🏃

Fitness + SSB

Academic preparation के साथ fitness, communication और personality skills पर काम करें।

Official UPSC Resources

UPSC Official Websiteupsc.gov.in ↗
CDS NotificationsExam Notifications ↗
Previous Year PapersUPSC Question Papers ↗
Online Applicationupsconline.nic.in ↗

महत्वपूर्ण सूचना

CDS की age, DOB window, gender, marital status, qualification, vacancies, fee और medical standards notification के अनुसार बदल सकते हैं। Latest UPSC notification को final authority मानें। citeturn0search0turn0search19