The Intercollegiate Horse Show Association (IHSA) is a national organization in which most colleges and universities participate. The country is divided into six zones with at least two regions in each zone; each region consists of ten to fifteen teams. William and Mary is a member of Zone 4, Region 1. All members of a given region meet for at least eight shows per year.

William and Mary competes against Mary Washington College, Goucher College, The University of Richmond, John Hopkins University, Towson, Prince George's Community College, The University of Maryland, Hood College, Saint Mary's College, American University, the Naval Academy, Mount Saint Mary's College, and Christopher Newport University. Most colleges host one horse show per year and provide the mounts for competition.

Right: Katherine Wallace and Madison Hannon hacking-off together at the UMBC Show October 4th, 2009

IHSA shows focus on English Hunt Seat Equitation at all levels. Riders range in ability from very beginners to riders with extensive showing experience. The classes at the shows are divided into six different divisions based upon show experience and number of years riding. Beginner riders do not compete against more advanced riders. Only the upper three divisions include a jumping portion at the shows. In the other divisions, the riders compete in only a hack (flat) class.

The Class Divisions are as follows:

8: Open Over Fences

7: Open Flat

6: Intermediate Over Fences

5: Intermediate Flat

4: Novice Over Fences

3: Novice Flat

2A: Beginner Walk/Trot/Canter

2B: Advanced Walk/Trot/Canter

1: Walk/Trot