Calvert US Mid Cap Core Responsible Index Fund Class A

Over

The fund invests in the common stock of each company in the index in approximately the same proportion as represented in the index itself. The fund will normally invest at least 95% of its net assets, including borrowings for investment purposes, in securities contained in the index. The index is composed of the common stocks of mid-size companies that operate their businesses in a manner consistent with The Calvert Principles for Responsible Investment (the “Calvert Principles”).