Since the publication of the current English-language Lectionary for Mass (a process completed in 2002), a variety of liturgical changes have expanded the possibilities for the Scripture readings that the church provides for proclamation on various occasions. These include, among many others,

• an expanded Vigil Mass for Pentecost;
• celebrations of new saints, such as Junipero Serra, Juan Diego, John XXIII, and John Paul II;
• new Votive Masses, such as those for The Mercy of God and the Day of Prayer for the Legal Protection of Unborn Children.

This new Lectionary for Mass Supplement, approved by the United States Conference of Catholic Bishops in June 2015, gathers together approved texts for a variety of new liturgical occasions into one elegant volume . Eminently readable and beautifully designed, with one sturdy ribbon bookmark, the Lectionary for Mass Supplement will complement the exceptional quality and format of current editions of the Lectionary for Mass."