Family law: child custody; changing the established custodial environment of a child; expand. Amends secs. 7 & 8 of 1970 PA 91 (722.27 & 722.28).

HB 5578 amends Michigan's Child Custody Act to clarify when courts may change a child's established custodial environment. It specifically allows a change if a parent proves the other parent was convicted of criminal sexual conduct against a minor (or found by clear evidence to have committed nonconsensual sexual penetration of a child) and the nonoffending parent knew of the conviction while permitting the child's access. The bill also protects military parents by requiring courts to ignore a parent's deployment absence in custody decisions, reinstating pre-deployment custody arrangements after return, and limiting temporary custody orders during deployment. Additionally, it tightens appeal standards for custody rulings, requiring courts to show legal error or abuse of discretion - not just factual disagreement - to overturn decisions.