Sentence segmentation, also known as sentence tokenization or sentence boundary disambiguation, is the task of splitting text into sentences. Sentence segmentation systems rely on rules that are either written by humans or learned automatically from annotated text data to identify occurrences of patterns within text. Since sentence segmentation is typically an early step in natural language processing (NLP) pipelines, performance of a sentence segmentation system can significantly influence performance on downstream tasks. In an NLP pipeline for processing clinical notes, sentence segmentation offers value for various tasks such as identifying discussions of certain topics during patient visits. However, because clinical notes do not follow the same structural and writing conventions as regular English text, approaches for many common NLP tasks in the general English domain do not yield similar performance when applied to clinical notes. Text structures that are common in clinical notes but absent in general English, such as medical abbreviations, numbered lists, and sentences terminated by new lines, can cause general sentence segmentation systems to perform poorly on clinical note corpora. To address the task of sentence segmentation in the clinical note domain, we introduce a transformer-based sentence segmentation model trained on notes from the MIMIC-III clinical database and compare its performance to those of existing systems. Evaluation is currently under way. We will evaluate the systems by collecting intrinsic metrics (precision, recall, and F1-score) and will also perform an extrinsic evaluation by exploring the use of sentence segmentation for identifying mentions of goal-of-care discussions within clinical notes.