Code of Federal Regulations Title 20. Employees' Benefits § 20.1002.153 If employment is interrupted by a period of service in the uniformed services, is the employee permitted upon request to use accrued vacation, annual or similar leave with pay during the service? Can the employer require the employee to use accrued leave during a period of service?

(a) If employment is interrupted by a period of service, the employee must be permitted upon request to use any accrued vacation, annual, or similar leave with pay during the period of service, in order to continue his or her civilian pay. However, the employee is not entitled to use sick leave that accrued with the civilian employer during a period of service in the uniformed services, unless the employer allows employees to use sick leave for any reason, or allows other similarly situated employees on comparable furlough or leave of absence to use accrued paid sick leave. Sick leave is usually not comparable to annual or vacation leave;  it is generally intended to provide income when the employee or a family member is ill and the employee is unable to work.

(b) The employer may not require the employee to use accrued vacation, annual, or similar leave during a period of service in the uniformed services.