The mechanisms by which hydrogen desorbs from Ti-3 AI-8 V-6 Cr-4 Mo-4 Zr in the presence of a native oxide film under vacuum were examined over a range of temperatures using thermal desorption spectroscopy (TDS) and X-ray photoelectron spectroscopy (XPS). Hydrogen release was extremely limited and not measured below 260 degreesC due to the thermal stability of the surface oxide. XPS experiments indicate that hydrogen release is not observed in vacuum until after the oxide film is completely dissolved. However, in the temperature range 325-490 degreesC, TDS measurements indicate that hydrogen desorption is bulk diffusion controlled with a high desorption activation energy (135-144 kJ/mol). XPS measurements in conjunction with H desorption measurements indicate a slow, but measurable desorption rate following oxide dissolution, with the presence of a high relative O content (25-50 atom %) at the metallic surface. H desorption is rationalized to be diffusion-Limited by an O-enriched Ti surface layer at these temperatures. Surface recombination controlled desorption was observed by TDS at temperatures exceeding 490 degreesC. XPS. results indicate that the transition from diffusion control to surface recombination control (and an increased desorption rate) is likely coincident with a reduction of the relative surface O content in the alloy to below 25 atom %. Qualitative desorption simulation results indicate agreement with a model that includes H egress by diffusion and surface recombination coupled in series. However, quantitative agreement cannot be obtained without accounting for the effect of the O-enriched surface layer on bulk H diffusion parameters.