Since its implementation in 2004, the Canadian English Language Benchmark Assessment for Nurses (CELBAN) has been accepted as evidence of language ability for licensure of internationally educated nurses (IENs) in Canada. This article focuses on the complexities of sustaining an occupation-specific assessment over time. The authors reference the seminal work of Epp and Lewis, who developed the original CELBAN test forms and aligned the test results with the Canadian Language Benchmarks (CLB), and then go on to describe a research and development project that was carried out under the direction of Touchstone Institute and overseen by the Centre for Canadian Language Benchmarks (CCLB) to renew the test model and develop additional content. This is followed by a discussion of the maintenance strategies required to sustain a secure assessment within the evolving Canadian context.