UPSC Combined Defence Services Examination (I) 2026 — Complete Guide

The UPSC Combined Defence Services (CDS) Examination is conducted twice a year by the Union Public Service Commission (UPSC) to recruit officers into the Indian Military Academy (IMA), Indian Naval Academy (INA), Air Force Academy (AFA), and Officers Training Academy (OTA) Chennai. It is one of the most respected pathways to becoming a Commissioned Officer in the Indian Armed Forces for graduates.

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UPSC CDS 1 2026 — At a Glance

Parameter	Details
Conducting Body	Union Public Service Commission (UPSC)
Exam	Combined Defence Services Examination (I) 2026
Academies	IMA Dehradun, INA Ezhimala, AFA Hyderabad/Dundigal, OTA Chennai
Mode of Exam	Offline (Paper & Pen, OMR-based)
Official Website	upsc.gov.in

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UPSC CDS 1 2026 — Important Dates

Event	Date
Notification Release	December 10, 2025
Application Start	December 10, 2025
Application Last Date	December 30, 2025
Admit Card Available	March/April 2026
CDS 1 Exam Date	April 12, 2026 (Sunday)
Written Result	May–June 2026
SSB Interviews	July–November 2026
Medical Examination	Post-SSB
Final Joining	January 2027 (IMA/INA/AFA/OTA courses)

Note: The application window for CDS 1 2026 has closed (December 30, 2025). Aspirants should prepare for CDS (II) 2026 — expected notification in May 2026.

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UPSC CDS 1 2026 — Vacancy Details

Academy	Vacancies (CDS 1 2026 — Approx.)
IMA Dehradun (Male only)	~100
INA Ezhimala (Male only, Naval Academy)	~32
AFA Dundigal / Hyderabad (Male only)	~32
OTA Chennai (Male — SSC Short Service Commission)	~175
OTA Chennai (Female — SSC Non-Technical)	~12
Total	~350 (approx.)

Previous cycles for reference: CDS II 2024 had 459 total vacancies; CDS I 2024 had 457 total vacancies.

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UPSC CDS 2026 — Eligibility Criteria

Academy-Wise Educational Qualification

Academy	Qualification Required
IMA Dehradun	Any Graduate from a recognized University
Officers Training Academy (OTA)	Any Graduate from a recognized University
Naval Academy (INA)	Engineering degree in specified Engineering disciplines (Electrical, Electronics, Mechanical, Aeronautical, Naval Architecture, Physics/Maths at degree level)
Air Force Academy (AFA)	Degree of a University (with Physics and Mathematics at 10+2 level) OR Bachelor of Engineering degree from a recognized University

Age Limit (as on January 1, 2026)

Academy	Age Requirement	Gender
IMA Dehradun	19–25 years (unmarried males)	Male only
INA Ezhimala	19–25 years (unmarried males)	Male only
AFA Dundigal	20–24 years (unmarried males)	Male only
OTA Chennai (Men)	19–25 years	Male only
OTA Chennai (Women)	19–25 years (married/unmarried/widowed)	Female

Birth date for CDS 1 2026: Born between January 2, 2001 and January 1, 2007 for most academies (exact dates confirmed in official notification).

Nationality

Candidate must be a citizen of India. Subjects of Nepal/Bhutan or persons of Indian origin from specified countries are also eligible with proper certification.

Marital Status

• IMA, INA, AFA: Only unmarried males eligible. Married candidates cannot apply.
• OTA: Both married and unmarried females are eligible. Males must be unmarried.

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UPSC CDS 1 2026 — Exam Pattern

For IMA, INA, AFA (3 Papers)

Paper	Subject	Total Marks	Duration
Paper 1	English	100	2 Hours
Paper 2	General Knowledge	100	2 Hours
Paper 3	Elementary Mathematics	100	2 Hours
Total		300	6 Hours (spread over one day)

For OTA Chennai (2 Papers)

Paper	Subject	Total Marks	Duration
Paper 1	English	100	2 Hours
Paper 2	General Knowledge	100	2 Hours
Total		200	4 Hours

Important Rules:

• Negative marking: 1/3rd mark deducted per wrong answer
• Question type: Objective (Multiple Choice, OMR-based)
• Minimum qualifying marks in each paper (percentage varies by year and UPSC discretion)

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UPSC CDS 2026 — Detailed Syllabus

English (Paper 1 — 100 Marks)

The English paper tests command over the language through:

• Reading Comprehension: 2–3 passages; questions on main idea, vocabulary in context, detail questions
• Vocabulary: Synonyms, Antonyms, Word Substitutions, Idioms & Phrases
• Grammar: Spot the Error, Fill in the Blanks, Sentence Improvement
• Ordering: Para Jumbles (sentence rearrangement)
• Active/Passive Voice, Direct/Indirect Speech
• Cloze Test: Blank-filling in a passage (word selection based on context)

General Knowledge (Paper 2 — 100 Marks)

History of India:

• Ancient India — Harappan culture, Vedic period, Mauryan empire
• Medieval India — Rajput period, Delhi Sultanate, Mughals
• Modern India — British period, 1857, Congress, Gandhian era, independence
• History of the World — Renaissance, WWI and WWII, Cold War, Decolonization

Geography:

• Indian geography — rivers, mountains, climate, states and capitals
• World geography — continents, major countries, time zones, important straits
• Physical geography — types of rocks, climate types, ocean currents
• Economic geography — agriculture patterns, mineral distribution

Indian Polity:

• Constitution — Preamble, Fundamental Rights
• Parliament — Lok Sabha, Rajya Sabha functions
• President, PM, Cabinet structure
• Judiciary — Supreme Court, High Courts

Indian Economy:

• Basics of Indian economy — GDP, sectors
• RBI functions, banking basics
• Union Budget, Fiscal Policy

Science — Physics, Chemistry, Biology:

• Physics: Laws of motion, electricity, magnetism, optics, heat, sound
• Chemistry: Elements, compounds, acids/bases, everyday chemistry
• Biology: Cell biology, nutrition, human body systems, immunity, diseases

Defence and Strategic Affairs (highly important for CDS):

• Indian Army structure — Commands, Corps, Divisions
• Major defence acquisitions — Tejas aircraft, INS submarines, missile systems
• Joint exercises — Tasman Saber, Vajra Prahar, Shakti (India-France)
• Defence organisations — DRDO, HAL, BEL, OFB
• Nuclear policy — No First Use; CTBT status

Current Affairs:

• National events — government schemes, appointments, national security
• International events — bilateral relations, UN resolutions, G20, BRICS
• Recent sports championships (India's performance)
• Awards — Bharat Ratna, Param Vir Chakra, Nobel Prize

Elementary Mathematics (Paper 3 — 100 Marks, for IMA/INA/AFA only)

Arithmetic:

• Number system: Natural numbers, integers, rational numbers
• HCF, LCM, Fractions, Decimals
• Percentages, Ratio and Proportion, Unitary Method
• Simple and Compound Interest
• Profit, Loss, Discount
• Time, Work, Time and Distance

Algebra:

• Basic algebraic identities
• Linear equations in one and two variables
• Quadratic equations and their roots
• Set theory: Union, Intersection, Complement

Geometry:

• Lines, angles, triangles (congruence and similarity theorems)
• Circles — chords, tangents, arcs
• Polygons — area and perimeter
• Quadrilaterals (parallelogram, rectangle, rhombus, trapezoid)

Trigonometry:

• Trigonometric ratios (sin, cos, tan, cosec, sec, cot)
• Simple trigonometric identities
• Heights and Distances (angles of elevation and depression)

Statistics:

• Mean, Median, Mode
• Tabulation of data
• Graphs — bar, pie, histograms
• Frequency distribution

Mensuration:

• Area of 2D shapes (rectangle, triangle, circle, trapezoid)
• Surface area and volume of 3D shapes (cube, cuboid, cylinder, cone, sphere)

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UPSC CDS — Previous Year Cut-Offs (Written, Out of 300 for IMA)

Year	IMA (Gen)	INA (Gen)	AFA (Gen)	OTA (Gen)
CDS I 2024	112 / 300	—	81 / 300	77 / 200
CDS II 2023	108 / 300	98 / 300	85 / 300	74 / 200
CDS I 2023	116 / 300	104 / 300	89 / 300	79 / 200
CDS II 2022	105 / 300	95 / 300	82 / 300	72 / 200

Written exam cut-offs are relatively moderate — the real challenge is cracking the SSB Interview (which 70%+ of written qualifiers fail).

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SSB Interview Process (5 Days)

After clearing the written exam, candidates go through the 5-day Services Selection Board (SSB) Interview:

Day	Activity
Day 1	Stage 1 Screening: OIR Tests (Intelligence Rating) + PP&DT (Picture Perception & Description Test)
Day 2	Psychology Tests: TAT (Thematic Apperception Test), WAT (Word Association Test), SRT (Situation Reaction Test), SDT (Self-Description Test)
Day 3–4	Group Testing: GD (Group Discussion), GPE (Group Planning Exercise), PGT (Progressive Group Task), HGT (Half Group Task), IOT (Individual Obstacles), Command Task, FGT (Final Group Task)
Day 5	Personal Interview + Conference (Final Decision) — Recommended or Not Recommended

SSB Marks: 900 (for IMA/INA/AFA) | 300 (for OTA) Final Merit: Written (300) + SSB (900) = 1200 for IMA/INA/AFA | Written (200) + SSB (300) = 500 for OTA

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CDS Officer Salary Structure

Upon joining as Lieutenant (IMA/INA/AFA) or Lieutenant (OTA):

Component	Amount
Basic Pay	₹56,100 (Level 10)
Military Service Pay (MSP)	₹15,500
HRA (30% of Basic — X city)	₹16,830
DA (55% of Basic)	~₹30,855
Kit Maintenance Allowance	₹20,000 (annually)
Total In-Hand (approx.)	₹85,000–₹1,05,000/month

Additional benefits: Free accommodation (army quarter), uniform provided, mess facilities, army canteen (CSD), free medical for self and family, 60 days annual leave, ECHS health scheme.

Career Progression: Lieutenant → Captain → Major → Lieutenant Colonel → Colonel → Brigadier → Major General → Lieutenant General → General (COAS)

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Preparation Strategy for UPSC CDS 2026

3-Month Plan (for CDS II 2026)

Month 1:

• English: 15 words per day from Norman Lewis; 1 editorial reading per day; basic grammar (Wren & Martin — Chapters on Tenses, Articles, Prepositions)
• GK: NCERT History Class 8–12 (Modern India focus); Polity basics (M. Laxmikanth Chapters 1–15)
• Maths: Arithmetic — Percentage, Profit/Loss, Interest, Time/Work (RS Aggarwal Class 10 level)

Month 2:

• English: Reading comprehension practice (3 passages per day); vocabulary test yourself
• GK: Geography (NCERT Physical Geography Class 11); Current Affairs (monthly compilation); Defence News — daily practice
• Maths: Geometry and Trigonometry; previous year CDS Maths papers

Month 3:

• 2 full-length CDS mock tests per week (English + GK + Maths papers)
• Current Affairs: Last 6 months — defence exercises, government schemes, international events
• Maths: Complete revision of all topics; error analysis on mocks

Best Books for UPSC CDS 2026

Subject	Book
English	S.P. Bakshi — Objective English (Arihant)
GK/History	Spectrum — A Brief History of Modern India
GK/Geography	NCERT Class 11 Physical Geography
Defence Current Affairs	Major Kalshi Classes Monthly Magazine
Mathematics	RS Aggarwal — Quantitative Aptitude (till Class 10 level)
Previous Papers	Pathfinder CDS by Arihant Publications

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Official Resources

Resource	Link
UPSC Official Website	upsc.gov.in
Apply Online	upsconline.nic.in
CDS Notification	UPSC Notifications Page
Previous Year Papers	UPSC Question Bank
Syllabus	UPSC Syllabus

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Last Updated: April 2026 | Source: Union Public Service Commission (UPSC), Government of India