Short answer: They get whatever the employer gives other employees on a comparable furlough or leave of absence, and if that varies by type of leave, the most favorable comparable treatment.
During service the employee is treated as on furlough or leave of absence, even if the employer labels them ‘terminated.’ They are entitled to the non-seniority rights and benefits the employer generally provides to employees with similar seniority, status and pay who are on furlough or leave of absence.
If those benefits vary by type of leave, the service member must get the most favorable treatment given to any comparable leave. Duration is often the most important comparison (a two-day funeral leave is not comparable to a long deployment), along with the purpose of the leave and whether the employee chooses when to take it. Vacation accrual is owed only if comparable leaves accrue it.
For group life, disability and other ancillary lines, check two things before a deployment: the employer’s written leave policy and each carrier’s continuation provision for employees not actively at work. If the employer keeps life coverage going for employees on other long leaves, it should do the same here.