SubmissionNumber#=%=#22 FinalPaperTitle#=%=#Zero-Shot, Fine-Tuned, and Retrieval-Augmented Extraction of Clinical Decisions with Corpus Boundary Diagnostics ShortPaperTitle#=%=# NumberOfPages#=%=# CopyrightSigned#=%=# JobTitle#==# Organization#==# Abstract#==#We present the CanSA system for the MedEx-ACT@ACL 2026 shared task, which requires extracting and classifying clinical decisions from ICU discharge summaries into nine DIC-TUM categories. We have developed three approaches: (1) a training-free system which consists of a preprocessing module that normalizes text and an inference engine combining zero shot LLMs with a RAG ensemble, (2) a supervised fine-tuning method which required training, and (3) a training-free retrieval-augmented pipeline employing TF–IDF-based lexical retrieval to surface in-context exemplars from the development corpus, combined with section aware chunking and structured extraction calls to a large language model. Our team's best submission achieved a Final Score of 0.41, ranking 34th out of 37 on the official test leaderboard. Author{1}{Firstname}#=%=#Mohammed Author{1}{Lastname}#=%=#Alliheedi Author{1}{Orcid}#=%=# Author{1}{Email}#=%=#malliheedi@bu.edu.sa Author{1}{Affiliation}#=%=#Al Baha University Author{2}{Firstname}#=%=#Robert E. Author{2}{Lastname}#=%=#Mercer Author{2}{Orcid}#=%=# Author{2}{Email}#=%=#mercer@csd.uwo.ca Author{2}{Affiliation}#=%=#University of Western Ontario Author{3}{Firstname}#=%=#Anemily V. Author{3}{Lastname}#=%=#Machina Author{3}{Username}#=%=#amachina Author{3}{Orcid}#=%=# Author{3}{Email}#=%=#anemily.machina@uwo.ca Author{3}{Affiliation}#=%=#University of Western Ontario Author{4}{Firstname}#=%=#Sudipta Singha Author{4}{Lastname}#=%=#Roy Author{4}{Orcid}#=%=# Author{4}{Email}#=%=#ssinghar@uwo.ca Author{4}{Affiliation}#=%=#University of Western Ontario Author{5}{Firstname}#=%=#Yetian Author{5}{Lastname}#=%=#Wang Author{5}{Orcid}#=%=# Author{5}{Email}#=%=#yetian.wang@uwaterloo.ca Author{5}{Affiliation}#=%=#University of Waterloo Author{6}{Firstname}#=%=#Xindi Author{6}{Lastname}#=%=#Wang Author{6}{Orcid}#=%=# Author{6}{Email}#=%=#xindi.wang@sdu.edu.cn Author{6}{Affiliation}#=%=#Shandong University ========== èéáğö