CDS Exam: Pattern, Syllabus, Eligibility and Preparation

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The CDS exam, or Combined Defence Services Examination, is a national-level written test conducted by the Union Public Service Commission (UPSC) for graduates who want to become officers in the Indian armed forces. It leads to training at the Indian Military Academy (IMA) in Dehradun, the Indian Naval Academy (INA) in Ezhimala, the Air Force Academy (AFA) in Dundigal, and the Officers Training Academy (OTA) in Chennai.

UPSC holds the CDS exam twice a year, as CDS (I) and CDS (II). Clearing the written test earns a Services Selection Board (SSB) interview, and the final merit list combines both. This guide covers the CDS exam pattern, syllabus, eligibility for each academy and how to prepare.

CDS at a glance

Full name	Combined Defence Services Examination
Conducted by	Union Public Service Commission (UPSC)
Exam level	National
Held	Twice a year (CDS I and CDS II), usually April and September
Mode	Pen-and-paper, objective (OMR)
Duration	2 hours per paper
Subjects	English, General Knowledge, Elementary Mathematics (OTA: English and GK only)
Total marks	300 written for IMA, INA and AFA; 200 for OTA
Negative marking	One third of the question’s marks for each wrong answer
Languages	English paper in English; GK and Maths in Hindi and English
Leads to	IMA, INA, AFA and OTA officer training
Official website	upsc.gov.in

CDS important dates

These dates update automatically from Kosuki’s exam calendar. “Announced” dates come from the official notice; “Expected” months are based on past years.

CDS (I) 2027

CDS (II) 2027

!Dates can change. Always confirm on the official website. Report a wrong date · How we check dates

What is the CDS exam?

The CDS exam is the graduate-level entry into the armed forces. Candidates choose which academies they want in their application. IMA, INA and AFA lead to a permanent commission for men. OTA leads to a short service commission and is open to both men and women.

Your academy choice decides which papers you write. IMA, INA and AFA candidates write all three papers. Candidates applying only for OTA write English and General Knowledge.

CDS eligibility

Age limits, marital status rules and education requirements differ by academy. The figures below are from the CDS (II) 2026 notification. Each notification gives exact birth-date windows.

Academy	Age	Education	Who can apply
IMA	19 to 24	Any bachelor’s degree	Unmarried men
INA	19 to 24	Engineering degree, or B.Sc. with Physics, with Physics and Maths at 10+2	Unmarried men
AFA	20 to 24 (up to 26 with a valid CPL)	Any degree or BE, with Physics and Maths at 10+2	Men; those under 25 must be unmarried
OTA (men)	19 to 25	Any bachelor’s degree	Unmarried men
OTA (women)	19 to 25	Any bachelor’s degree	Unmarried women, and issueless widows or divorcees

• Final-year degree students can apply, but must submit proof of passing by the date in the notification.
• Physical and medical standards apply and are checked after the SSB.

CDS exam pattern

Each paper is 2 hours and 100 marks. The English paper is set only in English. The GK and Elementary Mathematics papers are bilingual. In recent years, English and GK have had 120 questions each and Maths has had 100.

Paper	Questions (recent years)	Marks	Duration
English	120	100	2 hours
General Knowledge	120	100	2 hours
Elementary Mathematics (not for OTA)	100	100	2 hours
SSB for IMA, INA, AFA		300	About 5 days
SSB for OTA		200	About 5 days

CDS marking scheme

UPSC deducts one third of the marks assigned to a question for each wrong answer. Marking two options counts as a wrong answer. Unattempted questions carry no penalty. UPSC also fixes minimum qualifying marks in each paper, so one weak paper can stop you even with a decent total.

• English and GK: about 0.83 marks per question, with about 0.28 deducted per wrong answer.
• Elementary Mathematics: 1 mark per question, with about 0.33 deducted per wrong answer.
• Final merit: written marks plus SSB marks. Ties go to the higher written score, then higher GK marks, then the older candidate.

CDS syllabus

• English: grammar and usage, vocabulary, synonyms and antonyms, error spotting, sentence arrangement, cloze tests and reading comprehension.
• General Knowledge: current events, Indian history, geography, polity, economy, general science, and defence-related topics.
• Elementary Mathematics: arithmetic, algebra, trigonometry, geometry, mensuration and statistics at roughly Class 10 level.

CDS result, SSB interview and merit list

UPSC first publishes the written result as roll numbers of candidates who qualified for the SSB. The SSB has two stages. Stage I includes an intelligence rating test and a picture perception and description test. Only those who clear it continue to Stage II: interview, group testing tasks, psychology tests and a conference over about four days. AFA candidates also take the Computerized Pilot Selection System test.

After medicals, UPSC releases separate final merit lists for each academy. Because the OTA course starts later, its final list usually comes out separately from the IMA, INA and AFA list.

How to prepare for the CDS exam

English and GK are common to every academy, and together they decide most OTA selections. Treat them as the core of your plan. Maths is Class 10 level, so it rewards steady practice more than advanced study.

In English and GK you have about one minute per question. GK questions are either known or not, so do not linger. Save time for Maths, where calculation errors are the main risk.

• Solve at least five years of CDS papers for each subject. UPSC repeats question types, especially in English.
• For GK, revise NCERT History, Geography, Polity and Science books from Class 6 to 10, then add current affairs from the last year.
• Build vocabulary daily and practice sentence rearrangement and error spotting in timed sets.
• For Maths, revise Class 10 arithmetic, algebra, geometry and trigonometry, and learn shortcuts for percentage, ratio and time-work problems.
• Guess only when you can eliminate two options. With a one-third penalty, random guessing loses marks on average.
• Take full mock tests in the same order as the exam day. You can track mock scores and chapter progress in Kosuki.
• Prepare for the SSB alongside the written exam: fitness, clear communication and awareness of your own background.

How to apply for the CDS exam

1. Check the UPSC website for the CDS notification, which usually comes out several months before each sitting.
2. Complete or update your One Time Registration (OTR) on the UPSC online portal.
3. Fill in the CDS application form and select your academies in order of preference.
4. Upload your photo, signature and identity document.
5. Pay the fee online, unless you are in an exempt category.
6. Download the e-admit card closer to the exam and check your center and papers.

CDS FAQs

Related exam guides

• NDA: Pattern, Syllabus, Eligibility and Preparation
• AFCAT: Exam Pattern, Syllabus, Eligibility and Preparation

Sources

• www.upsc.gov.in/sites/default/files/Notif-CDS-II-2026-Engl-200526.pdf
• upsc.gov.in
• www.upscplanner.com/exams/upsc-cds

Last reviewed September 2026 against the official Union Public Service Commission notice and information brochure. Exam rules can change from year to year, so always confirm details on the official website before you apply. Kosuki is independent and is not connected with any exam body. Spotted something out of date? Write to contact@kosuki.com.