I know some people have had issues obtaining insurance, but I never had. Just been to the states and had no issues. Just be honest on the form, declare the type 1 diabetes. The companies are interested in how many times you have been hospitalised etc, but if you are well controlled and generally in good heath, the insurance is provided at a reasonable cost. I guess issues and higher premium may arise if you are not well controlled and have had seious hypos or associated conditions.