A refrigerator appliance includes a cabinet having an inner liner spaced apart from an outer wrapper and a trim breaker extending between the inner liner and the outer wrapper to define an insulating cavity therebetween. The trim breaker includes first and second opposing vertical portions, a top portion, a bottom portion, and a central portion. The top portion is integrally formed with each vertical portion at a respective upper corner, and the bottom portion is integrally formed with each vertical portion at a respective lower corner. A first plurality of ribs extends from an outer rim of the trim breaker and at least partially along the central portion, and a second plurality of ribs extends from the outer rim of at least one of the first and second vertical portions and across at least one of the upper and lower corners.