Short answer: Yes. Under the federal FMLA, an employer must maintain the employee’s group health coverage during job-protected leave on the same terms as if they were still working.
The Family and Medical Leave Act (which applies to employers with 50 or more employees) requires that an eligible employee’s group health coverage continue during FMLA leave on the same terms as active employment, including the employer’s normal share of the premium. The employee still owes their portion, and the employer can recover advanced premiums if the employee doesn’t return. For non-FMLA leave, continuation depends on the employer’s written policy and the carrier’s eligibility rules.