Chris von Csefalvay developed a Medicare Beneficiary Identifier (MBI) recognition feature for the microsoft/presidio repository, focusing on automated detection of US Medicare IDs in text. Leveraging Python, regular expressions, and unit testing, Chris implemented the UsMbiRecognizer to support both dashed and undashed MBI formats, enabling seamless integration into the existing recognizers framework. This work addressed the need for automated tagging of Medicare IDs, reducing manual review and improving data quality for downstream analytics. The feature was delivered production-ready, with attention to domain-specific pattern recognition and compliance requirements, reflecting a focused and technically robust engineering contribution within the project.