For benefit years beginning after the conversion date prescribed in section 75, unused benefit entitlement shall not be preserved pursuant to this section unless the commission receives a written statement from the individual's physician within 90 days after the commencement of the disability, within 90 days after the individual is advised of his or her rights by the commission, or if the individual is unable to submit the written statement due to a medical inability, within 90 days after the end of that medical inability the commission receives the written statement from the individual's physician. The written statement from the individual's physician shall certify all of the following:
MCL 421.28a