What CDS is
The Combined Defence Services Examination, conducted by UPSC, recruits graduates into four officer training academies: the Indian Military Academy, the Indian Naval Academy, the Air Force Academy, and the Officers Training Academy, which trains for a Short Service Commission rather than a permanent one. It is the graduate-level counterpart to NDA, which recruits directly from class 12, and it is the route for candidates who complete a degree first and then decide on a defence career.
Each academy trains for a different service and carries its own specific academic requirement, so a candidate’s degree subject genuinely determines which academies they can apply to, not just a general preference.
Who can apply
The Indian Military Academy and Officers Training Academy accept a bachelor’s degree in any discipline. The Indian Naval Academy requires a Bachelor of Engineering. The Air Force Academy requires a bachelor’s degree with Physics and Mathematics at the class 12 level, or a Bachelor of Engineering. The general age band is roughly 19 to 25 years, varying by academy, with the exact bounds set out fresh in each notification.
How the exam runs
The written examination is an OMR test covering English and General Knowledge for every academy, plus Elementary Mathematics for the Indian Military Academy, Indian Naval Academy and Air Force Academy candidates. Officers Training Academy candidates, training for a Short Service Commission, do not sit the Mathematics paper.
Candidates who clear the written cutoff proceed to the SSB Interview, the same multi-day process of psychological tests, group tasks and a personal interview that NDA uses, conducted at a designated SSB centre. Candidates who clear the SSB undergo a medical examination. Final selection combines written marks and SSB marks, with the medical and SSB stages carrying substantial weight in the outcome.
Preparing the application
UPSC specifies exact photograph and signature requirements in each notification rather than a fixed year to year standard, so check the current notification’s dimensions and file size before uploading. The tools on this site can resize your photograph to whatever specific target the notification states.
On exam day
Arrive at least an hour before the reporting time on your admit card, with the printed admit card, a government photo identification matching the name and photo on the admit card, one recent passport size photograph, and a black ballpoint pen for the OMR sheet. No electronic devices are permitted, and only material issued by UPSC at the centre may be used.
The SSB stage happens on a separate schedule and location, notified only to candidates who clear the written exam, and typically spans several days.
The official UPSC notification and website, linked above, carry the exact age bounds for each academy, vacancies and current schedule for the cycle you are applying to.