There is no difficulty in getting a deferrment if military positions are filled. Typically, there are two types of deferrments based on the needs of the navy: 1 year deferrments for an internship and full residency deferrments. 1 year deferrments go to operational commands as you can see on the bupers website through GMO detailers. There is a shortage of GMOs to fill billets so 1 year deferrments are likely (my opinion). Depending on your specialty and the needs of this country, you may ( I don't know the numbers) get an opportunity to complete your residency before having to do your payback.