CDS Exam Pattern 2027: Papers, Marks and SSB Guide

The CDS exam pattern decides how you split three papers, six hours and a firm negative-marking rule across one long day. UPSC conducts the Combined Defence Services Examination as an offline, objective-type written test followed by an SSB interview, and the structure differs slightly for IMA, INA and AFA on one side and OTA on the other.

This guide explains the pattern paper by paper: questions, marks, duration, negative marking, qualifying rules, the SSB stages and how the final merit list is built. It also turns the pattern into decisions you can act on, such as what one question is really worth, when a guess pays off and how to spend your time in each paper. Details tied to a cycle follow CDS II 2026 and are labelled as such; the structure itself has stayed the same across cycles.

Table of Contents

CDS Exam Pattern

The selection has three stages. The written exam and the SSB interview carry marks, while the medical examination is a pass or fail check.

The written exam is answered on an OMR sheet, and every question has four options. In CDS II 2026 the papers were held in separate sessions on the same day, 13 September 2026. Expect the same format again unless the notice says otherwise.

CDS Written Exam Pattern

Pattern for IMA, INA and AFA

Candidates for the Indian Military Academy, Indian Naval Academy and Air Force Academy appear in three papers, each of two hours.

Pattern for OTA

The Officers Training Academy has no Mathematics paper. Men and women apply under the same written pattern.

If you apply to OTA along with IMA, INA or AFA, you still sit all three papers because the Mathematics paper is needed for the other academies. Your OTA ranking is built from the English and General Knowledge papers only.

Qualifying rules in the written exam

• Sectional minimum: UPSC fixes a minimum of 20 percent in each paper, which is 20 marks out of 100. Scoring below it in even one paper ends your candidature, whatever your total.

• Aggregate cut-off: After the sectional check, UPSC shortlists candidates for the SSB using an academy-wise aggregate cut-off.

• No normalisation: Each paper is held in a single sitting with one question paper. There are no shifts to equate, so the raw marks you earn are the marks that count.

• Offline mode: This is a pen-and-paper exam at an allotted centre, not a computer-based test.

Marking Scheme and Negative Marking

Every paper has the same total of 100 marks, but the marks per question are not identical because the number of questions differs.

• Wrong answers: One-third of the marks assigned to the question is deducted for each wrong answer.

• Unattempted questions: No marks are deducted when you leave a question blank.

• More than one answer: Under the standard UPSC rule, marking more than one option is treated as a wrong answer even if one of them is correct, so shade one option only.

A worked example

Suppose you attempt 100 of the 120 English questions, with 80 right and 20 wrong. You earn 80 x 0.833, which is about 66.67 marks, and lose 20 x 0.278, which is about 5.56 marks. Your score is about 61.11 out of 100. Had you skipped the 20 shaky questions entirely, you would have kept 66.67. The wrong answers cost you more than five marks, which is why choosing which questions to attempt matters as much as knowing the answers.

What the Pattern Means for You

Know when a guess pays off

Because the penalty is one-third of the marks, the break-even point is a 25 percent chance of being right. With four options, a pure guess sits exactly on that line, so on average it neither gains nor loses marks. The moment you can remove one clearly wrong option, your chance rises to one in three and the guess starts to pay. Remove two options and it is one in two. This is why elimination practice is more valuable than blind attempts.

Do not neglect your weakest paper

The 20 percent sectional minimum is a hard gate. A candidate who scores well in English and General Knowledge but falls below 20 marks in Mathematics is out, even with a strong total. A balanced performance across all three papers is safer than excellence in two and neglect of one. If Mathematics is your weak area, protect the 20 marks first and then build upward from there.

Your academy choice changes your preparation

Candidates applying only to OTA can drop Mathematics from their plan and put the saved time into English and General Knowledge, which carry the whole written score. Anyone listing IMA, INA or AFA needs all three papers. The permanent commission routes carry a larger SSB weightage as well, 300 marks against 200 for OTA.

Read the numbers behind the pattern

In CDS I 2025, the last qualified candidate for IMA scored 120 out of 300 in the written exam, which is 40 percent, and the last recommended candidate scored 243 out of 600 in the final merit. These are previous-cycle figures from UPSC, and they move with difficulty and applicants, but they show that the written exam rewards steady accuracy rather than perfection.

SSB Interview Pattern

Candidates who clear the written exam are called to a Services Selection Centre. The SSB tests personality and officer-like qualities in two stages, and only those who clear Stage I move on to Stage II.

The Interviewing Officer, the Group Testing Officer and the psychologist each assess you independently, and there is no separate weightage for each test. The SSB is marked out of 300 for IMA, INA and AFA and out of 200 for OTA. There is no fixed syllabus, so preparation means clear communication, honest self-awareness, fitness and regular reading on current and defence affairs.

Medical Examination and Final Merit

Candidates recommended by the SSB undergo a medical examination by a board of service medical officers. It is a fitness check against the standards of the service concerned, and failing it removes you from the list.

The final merit list adds your written marks and your SSB marks. For IMA, INA and AFA that is 300 plus 300, a total of 600. For OTA it is 200 plus 200, a total of 400. The written exam and the SSB therefore carry equal weight.

As an illustration only, an IMA candidate with 150 out of 300 in the written exam and 100 out of 300 in the SSB would have 250 out of 600. This is not a prediction of any cut-off.

How UPSC breaks ties

Where two or more candidates have the same aggregate, UPSC ranks them in this order:

1. Written total: For IMA, INA and AFA, the candidate with more marks in Papers I, II and III together ranks higher. For OTA, the English and General Knowledge total is used.

2. General Knowledge: If still equal, the candidate with more marks in Paper II ranks higher.

3. Age: If still equal, the candidate senior in age ranks higher.

Time Management and Exam-Day Strategy

Each paper allows two hours. The plans below are practical suggestions based on the pattern, not UPSC rules, so adjust them after a few full mocks.

• Plan for fatigue: Three papers in one day test concentration as much as knowledge. Practise full-length sets in the same sequence so your third paper does not feel new.

• Shade carefully: Decide your answer first, then mark it once. Erasing or double-marking can cost you the question.

• Keep an accuracy target: Aim to keep wrong answers below one in five of your attempts in each paper, then raise the bar as your mocks improve.

Check Before You Trust Older Pages

Pattern details get copied from page to page, and mistakes travel with them. Before relying on any pattern table, check these points:

• Mode: The CDS written exam is offline. Some pages still describe it as online.

• OTA papers: OTA has two papers and no Mathematics. A page listing three papers for OTA is wrong.

• Total marks: The written total is 300 for IMA, INA and AFA and 200 for OTA, followed by SSB marks of 300 and 200.

• Negative marking: The deduction is one-third of the question's marks, not a flat 0.33 in every paper.

UPSC publishes the exact scheme in the examination notice for each cycle. Confirm it on the official UPSC website before you plan your preparation.