Costa Rica's Gender Parity Electoral Code — 49% Women in Legislature (2009–2026)

Costa Rica's 2009 Electoral Code (Código Electoral) mandates that 50% of candidacies be women, with alternating male-female placement enforced both vertically (within each district list) and horizontally (across all districts). The Tribunal Supremo de Elecciones (TSE) rejects any non-compliant candidate list before it reaches the ballot.

To close the design gap seen in earlier regional quota systems, where parties placed women too low on lists to be elected, and to achieve genuine gender parity in the Legislative Assembly.

TSE reviews and rejects non-compliant party lists ahead of each election, enforcing the dual-axis (vertical and horizontal) alternation rule across all parties and districts.

Women's share of the 57-seat Legislative Assembly rose in a near-linear progression: 38.6% (2014–2018), 45.6%/26 seats (2018–2022), and 49.1%/28 seats (2022–2026), culminating in a historic female majority after the February 2026 elections.

Academic assessments (Americas Quarterly 2023) attribute the results to the dual-axis alternation mechanism rather than a simple percentage target, and cite Costa Rica alongside Bolivia and Mexico as a model of strong quota enforcement; a remaining gap persists in single-member executive races (presidency, vice-presidency, mayors) where list-alternation rules do not apply.