Health Professions Scholarship Program (HPSP) and Uniformed Services University of the Health Sciences (USUHS) students have the same chances of getting their residency of choice as civilian students, and the Military will never dictate which specialty you choose. In general, the more competitive you are as a student, and the more programs you apply to, the better your chances of matching. The availability of residency slots, however, depends on the Military's need at that particular time and how competitive the residency is overall.
Students who do not receive their first specialty choice may elect to take a transitional year internship and reapply for their first specialty choice in the following years. Unlike students in the civilian match, HPSP and USUHS students will receive internship training.
If you have a specialty in mind and are wondering about the chances of getting the residency of your choice, contact a recruiter.