Introduction: The Medical Text Indexer (MTI) has been incredibly impactful, with a notable decrease in the time it takes a MEDLINE citation to receive MeSH indexing. However, further work is needed to address some well documented issues around the indexing genes and chemical compounds, and their impact on information retrieval. To investigate these issues, this research pursues the following research questions: RQ1. Is there a relationship between indexing method or journal impact factor (JIF) and how well MeSH terms align with keywords and chemical symbols? RQ2. Is there a relationship between indexing method or JIF and the term usage frequencies among MeSH, keywords, and chemical symbols? Methods: The research method analyzed the indexing in a sample of MEDLINE citations. 648 citations published between January 2021 and December 2023 were randomly selected and relevant information fields extracted via NLM’s efetch and xtract tools. Journal impact factor data was downloaded from Clarivate. Using R, a n-gram analysis and the relative frequency of each term will address RQ1 and RQ2, respectively. Results: Preliminary results and interpretation of results for RQ1 using an n-gram word model and relative frequency results for RQ2 will be presented. Discussion: We will discuss the results of comparing term alignment in the context of information retrieval and term use frequency in the context of MTI performance and optimization. Overall implications for information retrieval and instruction in a health libraries context will be addressed.