UPSC CMS 2023 Previous Year Questions

Paper I saw heavy testing of rheumatology, haematology, and paediatric infectious diseases. Paper II had a strong focus on oncology (surgical and gynaecological), PSM calculations (sensitivity, specificity, NNT), and family planning. The most striking feature of 2023 was the dramatic rise in Gastroenterology, which surged to 19 questions in Paper I — the highest single-topic count across all years and all subjects. Endocrinology followed at 17 questions, while Infectious Disease and Cardiology contributed 16 and 14 questions respectively, all presented with increasing clinical vignette complexity. In Paper II, Obstetrics overtook Gynaecology for the first time in the 2020–2025 series with 22 versus 18 questions, a reversal of the pattern seen in 2020–2022 where Gynaecology had consistently led. GI Surgery declined to 12 questions, suggesting a partial correction from its 2021–2022 highs. PSM questions included more calculation-heavy biostatistics problems than any previous year.

UPSC released provisional and final answer keys for 2023. Several disputed answers were revised following candidate representations. The 2023 paper had a particularly high number of representations in the Medicine section, where clinical vignette-based questions sometimes had multiple defensible answers depending on the guideline referenced. CMS Prep marks all such questions and provides explanatory notes for both the official answer and the commonly argued alternative. Always cross-check with the final UPSC key published on upsc.gov.in.

Download the UPSC CMS 2023 question paper PDF and official answer key from our Telegram channel.

Gastroenterology's rise to 19 questions was the defining feature of Paper I 2023. Liver disease (cirrhosis, hepatitis, portal hypertension) and GI bleeding management dominated the sub-topics. Endocrinology at 17 questions featured complex diabetes case studies and thyroid nodule workup algorithms. Infectious Disease maintained its stronghold with questions on tuberculosis, HIV, and tropical infections. Notably, Neurology dropped to 5 questions — its lowest level in the series — while Cardiology gained significantly. This intra-paper redistribution meant candidates who over-invested in Neurology were caught off guard.

Obstetrics reclaiming the top spot at 22 questions was a significant pattern shift. Questions focused on labour complications, foetal surveillance, and obstetric emergencies rather than routine antenatal care. GI Surgery's decline to 12 questions was the first dip since its 2021 surge, though it remained a major topic. Vascular Surgery appeared as a distinct category with 4 questions on peripheral vascular disease and varicose veins. Orthopaedics gained ground with 6 questions covering fractures, dislocations, and bone tumours.

2023 marked a shift toward applied clinical reasoning, with Gastroenterology, Endocrinology, and Infectious Disease questions in Paper I built around patient vignettes rather than direct recall. Obstetrics overtook Gynaecology as the most-tested Paper II topic. The paper was widely considered the most difficult in the 2020–2023 period by aspirants, primarily because of the Gastroenterology surge that penalised candidates who had not allocated sufficient revision time to GI and hepatology topics. The increased Biostatistics calculations in PSM also added time pressure. Multi-statement questions with subtle wording differences made negative marking a real risk, requiring careful reading of each option.

The 2023 paper represents a pivot point in the series. It is the year where Gastroenterology peaked and where the clinical vignette style became the default rather than the exception. For preparation strategy, this paper is best used as a difficulty benchmark — if you can score well on the 2023 paper, you are well-prepared for the applied reasoning demanded in later years. Compare the Obstetrics-Gynaecology reversal here with 2024 to see if the trend continued. The 2023 paper also signals the increasing importance of Biostatistics in PSM, a trend that accelerated in 2024 and 2025. Use this paper in the later stages of your revision to test your ability to handle clinical reasoning under time pressure.

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.