Generally revise TRS laws on when retired teachers can return to work after retirement

This bill revises Montana's Teachers' Retirement System rules regarding when retired teachers can return to work, extending the required break-in-service period from 120 to 150 calendar days for those retiring after January 1, 2024. The law applies to retired teachers who wish to be re-employed in positions reportable to the retirement system and clarifies that this waiting period includes various work arrangements like independent contracting or temporary service. Retired teachers may still work as substitutes for temporarily absent teachers or mentor new teachers for up to 45 days during the break-in-service period without penalty, provided they meet specific conditions. The bill also outlines penalties for violations, including repayment of retirement benefits with interest and restoration to active member status, and sets the new rules to take effect on July 1, 2025, with provisions expiring on June 30, 2029.