Proposition 2½ is a Massachusetts law passed in 1980 that limits property tax increases. It restricts the amount that local governments can raise property taxes to 2.5% of the assessed value of a property each year. Additionally, it requires voter approval for any tax increases beyond this limit, ensuring that residents have a say in local tax decisions. The law was designed to provide financial relief to homeowners and prevent excessive taxation. It has had a significant impact on local budgets and funding for services such as education and public safety, often leading to budget constraints for municipalities across the state.