For decades, the SSN was a go-to data point for verifying insurance coverage. In the absence of a national patient identifier, it served as a consistent way to match individuals to their insurance records across health systems and payers. However, many patients do not have SSNs, and concerns about data privacy, duplication and identity theft led providers and payers to phase out SSNs. Although SSNs may still be collected during enrolment for administrative use, industry best practice now discourages using SSNs unless absolutely necessary.