OBJECTIVES: Published ISPOR guidelines indicate that new economic models should be subjected to through internal testing and debugging.  Moreover, evidence that this has been done should be provided.  Currently there are few published examples of such internal validation work.  The aim of the present analysis was to perform verification and validation analyses of a novel model for Type 1 Diabetes (the PRIME Diabetes Model). METHODS: Source code (Java) for the T1D PRIME Diabetes Model was delivered to an independent third party.  Program code was reviewed for syntax errors and tested via a separate software environment.  This process included using null and extreme input values to test whether the expected outputs were produced.  Replication tests using equivalent endpoint values were also performed.  Verification queries were resolved by discussion and the findings of the analysis were described in a report.  RESULTS: Internal validation confirmed all numbers and formulas collected from the literature and examined whether they were correctly implemented in the source code. Face validity was established with regard to the model’s structure, use of available clinical evidence, problem formulation and results.  Given that the PRIME Diabetes Model is programmed in Java, MATLAB was used to validate model components independently and results were tested at patient mean levels as well as the corner cases of minimum and maximum values in order to ensure the model produced valid results over the entire range of patient characteristics. The model passed both internal and face and validity reviews. CONCLUSIONS: Published verification analyses in line with ISPOR guidance for all new health economic models would improve transparency and provide a valuable resource for health care decision makers.  Using the PRIME Diabetes Model, the present analysis provides a real-world example of how verification and validation analyses can be performed and reported.