Healthcare administration generates large volumes of textual data, including clinical notes, billing documentation, incident narratives, portal messages, and operational records. These data create administrative burden but also provide opportunities for natural language processing to support documentation, coding, communication, safety review, and workflow automation. This systematic review examined natural language processing models applied to healthcare administration from 2017 to 2024. The review focused on five domains: clinical documentation, coding support, incident reporting, patient communication, and workflow automation. A PRISMA 2020-compliant review was conducted using structured searches of PubMed, Scopus, IEEE Xplore, and Web of Science for studies published between 2017 and 2024. Eligible studies were screened by two reviewers, extracted using a structured template, and synthesized narratively by administrative domain, model type, evaluation approach, and implementation maturity. Transformer-based models were increasingly prominent across the reviewed literature, particularly in documentation support, automated coding, and clinical text classification. Clinical documentation and coding support had the strongest evidence base, while incident reporting, patient communication, and workflow automation remained less mature and less frequently evaluated in real-world settings. Natural language processing for healthcare administration is technically promising, but most applications remain at the retrospective or proof-of-concept stage. Prospective validation, workflow integration, governance, and human oversight are needed before widespread operational adoption.