Exam prep·India· 6 min read

CDS Exam Guide

A neutral, factual overview of the Combined Defence Services (CDS) Examination — what it is, the broad selection stages, and the academies it leads to — with all specifics deferred to the official UPSC source.

Key facts

Conducting body: Union Public Service Commission (UPSC)
Mode: Offline (written examination)
Frequency: Twice a year (CDS I and CDS II)
Leads to: IMA, INA, AFA, OTA
Official site: upsc.gov.in

What the CDS Examination is

The Combined Defence Services (CDS) Examination is conducted by the Union Public Service Commission (UPSC) twice a year. It is a route to join the Indian Army, Navy, and Air Force as commissioned officers through the Indian Military Academy (IMA), Indian Naval Academy (INA), Air Force Academy (AFA), and Officers' Training Academy (OTA).

The examination is a written test, followed by an interview conducted by the Services Selection Board (SSB) for candidates who qualify the written stage.

Indian Military Academy (IMA) — Army permanent commission
Indian Naval Academy (INA) — Navy permanent commission
Air Force Academy (AFA) — Air Force permanent commission
Officers' Training Academy (OTA) — Army short-service commission

Selection stages

The broad selection process involves two main stages: a written examination administered by UPSC, and a Services Selection Board (SSB) interview for those who qualify. Medical standards are also assessed. The exact structure, subjects, and marks allocation are set in the official UPSC notification each cycle.

Written examination (conducted by UPSC)
Services Selection Board (SSB) interview
Medical examination

Broad eligibility

Eligibility varies by academy. The IMA entry generally requires any graduation; the INA entry requires a degree in engineering (B.E./B.Tech) with Physics and Mathematics at the 10+2 level; the AFA entry generally requires graduation with Physics and Mathematics at the 10+2 level, or an engineering degree. The OTA entry is open to graduates and final-year students. Age limits and subject requirements differ by entry and are set officially each cycle.

Always check the current-year UPSC CDS notification for exact eligibility — rules can change.

How to approach preparation

The written examination typically covers English, General Knowledge, and Elementary Mathematics (the mathematics paper applies to IMA/INA/AFA entries). Building a strong reading habit, practising current affairs, and working through mathematics fundamentals all support solid preparation.

Physical fitness matters for the SSB stage and beyond; developing it alongside academic preparation is advisable. No preparation can guarantee selection — the process is competitive and multi-stage.

Use official information

Vacancy counts, age limits, cut-offs, and attempt rules are set by UPSC each cycle and are subject to change. This guide does not quote any of those figures. Confirm all current details in the official UPSC CDS notification on upsc.gov.in before applying.

Frequently asked questions

Who conducts the CDS Examination?

The Combined Defence Services Examination is conducted by the Union Public Service Commission (UPSC), generally twice a year (CDS I and CDS II). Successful candidates then appear for the SSB interview.

What is the minimum qualification for CDS?

It varies by academy. The IMA entry generally requires any graduation; the INA entry requires an engineering degree (B.E./B.Tech) with Physics and Mathematics at the 10+2 level; the AFA entry generally requires graduation with Physics and Mathematics; the OTA entry is open to graduates and final-year students. Confirm exact requirements in the current UPSC notification.

Is CDS for all three armed forces?

Yes. CDS covers entries to the Indian Army (IMA, OTA), Indian Navy (INA), and Indian Air Force (AFA). Each academy has its own eligibility and selection criteria — check the official notification for the differences.

Official sources

This guide explains the process and is for guidance only. Eligibility, dates, fees and rules change every year — always confirm the current details on the official site before you act.

Verified against: Union Public Service Commission (UPSC) — official site.

Last verified: 2026-06-06.