UPSC CMS 2021 Previous Year Questions

Paper I had notable questions on COVID-19 management protocols, updated hypertension and diabetes guidelines, and paediatric nutrition. Paper II covered laparoscopic cholecystectomy, IVF basics, and updated WHO growth standards. Gastroenterology surged to become the most-tested Paper I subject with 13 questions, a significant jump from 9 in 2020. Neurology maintained its high representation with 12 questions, covering stroke, epilepsy, and neuropathies. Infectious Disease held steady at 12 questions, with several directly referencing COVID-19 pathophysiology, investigation, and management guidelines that were evolving at the time. In Paper II, GI Surgery saw a major increase to 17 questions, reflecting UPSC's growing interest in surgical management of gastrointestinal conditions. Obstetrics and Gynaecology were nearly equally split at 20 and 21 questions respectively, with OBG questions featuring more clinical scenario framing than the previous year. Immunization under PSM gained attention with 7 questions, testing knowledge of the National Immunization Schedule and vaccine-preventable diseases.

UPSC CMS 2021 official answer keys are available on the UPSC website. Download the full PDF via the Telegram channel link below. Some questions in 2021 generated controversy regarding correct options, particularly in the Medicine section where updated treatment guidelines conflicted with textbook content. CMS Prep's answer key notes these discrepancies and references the specific guidelines and textbook editions that support each answer. Always verify against the official UPSC key when it matters most.

Download the UPSC CMS 2021 question paper PDF and official answer key from our Telegram channel.

The most notable shift in 2021 Paper I was Gastroenterology overtaking Infectious Disease as the top-tested subject. Peptic ulcer disease, liver cirrhosis complications, and inflammatory bowel disease were all prominently featured. Pediatrics weightage increased from 24 to 29 questions, with Developmental milestones and Genetics gaining more attention. Nephrology dropped to just 4 questions, a significant decrease from 9 in 2020, covering only acute kidney injury and basic glomerulonephritis concepts.

Paper II in 2021 saw GI Surgery nearly double its share from 7 to 17 questions, making it the third most-tested topic after the OBG subjects. Appendicitis, cholecystitis, intestinal obstruction, and basics of laparoscopic surgery were heavily covered. The PSM section maintained its 40-question allocation with a balanced split between Communicable Diseases, Immunization, and Biostatistics. International Health appeared as a tested topic for the first time in this cycle, with questions on WHO initiatives and global disease burden.

2021 introduced a noticeably higher share of multi-statement and 'EXCEPT' format questions, especially in Paper II Obstetrics and Gynaecology. Gastroenterology dominated Paper I, requiring deeper clinical correlation than 2020. The inclusion of COVID-19 specific questions was a first for UPSC CMS, requiring aspirants to stay updated with rapidly changing management protocols rather than relying solely on textbooks. This shift caught many candidates off guard, as traditional preparation focused on established textbook content. The paper was widely considered more difficult than 2020, primarily because of the increased ambiguity in multi-statement options and the need to apply current clinical guidelines to unfamiliar clinical scenarios.

The 2021 paper is the transitional year in the 2020–2025 series. It bridges the straightforward recall style of 2020 with the more applied, scenario-driven approach that solidified in 2022 and beyond. When using this paper for practice, pay special attention to how UPSC framed COVID-19 questions — this pattern of testing current clinical developments continued in later years with evolving guidelines in endocrinology and cardiology. Compare the GI Surgery surge in 2021 (17 questions) with the sustained levels in 2022 (16 questions) to understand that this was not a one-time spike but a structural shift in UPSC's subject priorities. Practice this paper after mastering 2020, ideally in the middle of your revision cycle.

See how this year compares to all six years of UPSC CMS papers — subject weightage shifts, topic trends, and a measurable difficulty trend across 2020–2025.