Social Democratic Institutional Bloc

The Social Democratic Institutional Bloc (Spanish: Bloque Institucional Social Démocrata, or BIS) is a left-wing and social democratic political party of the Dominican Republic. It first contested national elections in 1994 when it was part of a Dominican Revolutionary Party-led alliance that won the Congressional elections. It was again part of the winning PRD bloc in the 1998 elections, before switching its allegiance to the Dominican Liberation Party for the 2002 elections. In the 2006 elections it was part of the victorious Progressive Bloc.