Mission Index Guide for Mortgage-Backed Securities

The document is a guide detailing the Mission Index, which serves as a disclosure solution for mortgage-backed securities (MBS) issued by Freddie Mac and Fannie Mae. It outlines the criteria and methodology used to evaluate loans within the index, focusing on addressing housing challenges for lower- and moderate-income borrowers. The guide specifies two versions of the Mission Index criteria, Version 1.0 and Version 1.1, each applicable to different issuance periods. It explains how loans are assessed against defined mission criteria, which are categorized into income, borrower, and property dimensions. The Mission Criteria Share (MCS) and Mission Density Score (MDS) are introduced as key metrics for evaluating the alignment of loans with mission objectives. The document includes detailed descriptions of the criteria, the scoring methodology, and the calculation of the MCS and MDS, ensuring transparency for investors regarding the social impact of the securities. Additionally, it provides a glossary for further clarification of terms used within the index.