The Constitution (One Hundred and Twenty-Eighth Amendment) Bill, 2023, passed both Houses of Parliament in September 2023, providing one-third reservation for women in Lok Sabha and State Legislative Assemblies. However, the reservation is contingent on a delimitation exercise following the next Census. The Bill amends Articles 330A and 332A. It does not extend reservation to Rajya Sabha or State Legislative Councils. The law is formally titled the Nari Shakti Vandan Adhiniyam.

The Nari Shakti Vandan Adhiniyam, 2023 is a landmark constitutional amendment that has been debated since the 1990s. The original Women's Reservation Bill was first introduced in 1996 and lapsed multiple times across successive Lok Sabhas due to political deadlock — primarily over demands for sub-quotas for OBC and Muslim women within the reserved seats. The 2023 Bill was introduced in the first session of the newly inaugurated Parliament building and passed with near-unanimous support.

The key constitutional mechanism is rotation: reserved constituencies will rotate after each delimitation exercise, preventing any single constituency from being permanently reserved. The reservation applies to seats already reserved for SCs and STs, meaning one-third of SC/ST seats will also go to women of those communities.

The critical political catch is the delimitation trigger. Reservation will not come into effect until after the next Census is conducted and a fresh delimitation is completed — effectively deferring actual implementation to 2029 or beyond, since the Census was delayed post-2021. Critics argue this built-in delay is a political compromise, not a constitutional necessity. For exam purposes, the distinction between what the Bill does immediately versus what requires future action is the most tested analytical dimension.