The effects of multiaxial loading, temperature, and time on the failure characteristics of an adhesive are studied. This paper documents the use of extensive and varied test data in the development of a new multiaxial, temperature, and time-dependent (MATT) failure model. This new failure model employs a combination-of the Tsai-Wu (or a modified Drucker Prager) failure criterion and a linear cumulative damage failure model. The model is developed using pure tensile and pure shear failure data. Verification of the accuracy of the model is evaluated using multiaxial and creep test data. Model development and verification testing was completed with a combination of tensile adhesion button and napkin ring test specimens. The model is shown to be very accurate for a wide range of load combinations, temperatures, and failure times.