Must I sign a medical release as part of a medical certification?

No. An employer may not require an employee to sign a release or waiver as part of the medical certification process. The regulations specifically state that completing any such authorization is at the employee’s discretion. Whenever an employer requests a medical certification, however, it is the employee’s responsibility to provide the employer with a complete and sufficient certification. If an employee does not provide either a complete and sufficient certification or an authorization allowing the health care provider to provide a complete and sufficient certification to the employer, the employee's request for FMLA leave may be denied.