The WTA Tier I tournaments were Women's Tennis Association tennis elite tournaments held from 1988 until 2008 season. Minimum prize money, from 2004 is $1,340,000. Two of the ten Tier I tournaments (Indian Wells and Miami) are played simultaneously with the ATP Tour Masters Series tournaments in those cities.
From 2009 WTA Tour, WTA changed tournament categories, so that majority of Tier I and Tier II tournaments from last seasons are in one category, WTA Premier Tournaments.
Read more about WTA Tier I Tournaments: Events, Winners, Singles Titles Matrix, Trivia