Mexico’s 2027 election: how the Chamber of Deputies is elected, dates and how to vote

The election will be held on Sunday 6 June 2027. The law sets ordinary federal elections on the first Sunday of June, and the Chamber of Deputies is renewed every three years (LGIPE, article 22). Election day is a non-working day throughout the country.

The federal electoral process began in September 2026, when the General Council of the National Electoral Institute (INE) opened it. In July 2026 the INE approved the comprehensive plan and timetable for the 2026–2027 federal process (agreement INE/CG479/2026).

The Chamber of Deputies, the lower house of the Congress of the Union, is elected in full every three years, and each deputy is elected together with a substitute (suplente) (Constitution, article 51). Among other things, it approves the federal budget each year and, together with the Senate, the laws and changes to the Constitution. The Senate and the presidency are not elected in 2027.

The same day, all 32 states hold local elections: 17 governorships, local congresses and town councils, at the same polling station. There is no judicial election in 2027: a constitutional reform published on 2 June 2026 moved it to the first Sunday of June 2028.

Sitting federal deputies can still stand for immediate re-election in 2027. The constitutional reform of 1 April 2025 bans it, but its transitional articles apply the ban only from the 2030 elections.

Each voter has a single vote for deputies, which counts twice:

1. 300 district seats. The country is divided into 300 single-member districts of similar population, with at least two in each state. In each one, the candidate with the most votes wins, in a single round (Constitution, articles 52 and 53).
2. 200 proportional seats. The same votes are added up for each party across the country, and 200 seats are shared out among the parties in proportion to their votes, from closed lists in five regions (circunscripciones) of 40 seats each. The lists alternate women and men (articles 53 and 54).
3. The 3% threshold. Only parties with at least 3% of the valid vote take part in sharing out the proportional seats. A national party that does not reach 3% also loses its registration (articles 41 and 54).
4. Limits. No party may have more than 300 deputies in total, and no party’s share of the Chamber may exceed its share of the national vote by more than eight points, unless it is due only to district wins (article 54). These limits apply to each party, not to each coalition.

In 2024 the INE applied the over-representation limit party by party, not by coalition, and the Electoral Tribunal of the Federal Judiciary (TEPJF) upheld that allocation.

The over-representation caps, coalitions and the 2024 seat allocation are explained in more detail in the analysis «How Mexico elects its 500 federal deputies in 2027».

As of 24/10/2026, eight national political parties are registered with the INE and can stand in the federal election: Morena, the National Action Party (PAN), the Institutional Revolutionary Party (PRI), the Ecologist Green Party of Mexico (PVEM), the Labor Party (PT), Movimiento Ciudadano (MC), SOMOS and Partido PAZ. SOMOS and Partido PAZ were registered in 2026 and 2027 is their first election. The test compares your answers with each of these 8 parties separately.

Parties can run together in a coalition in all or some of the districts. On the ballot each party still appears with its own emblem, and you vote for one party: the votes are added up for the coalition’s candidate in the district and counted for each party for the proportional seats. Morena, the PVEM and the PT have announced that they will run together; coalitions are only final when the INE registers their agreements. Parties standing in their first election, like SOMOS and Partido PAZ, cannot join a coalition (LGPP, articles 85 and 87).

What each party stands for, question by question, is on the party pages.

Each party’s page: PAN · PRI · PVEM · PT · MC · Morena · PAZ · SOMOS

Who can vote. Mexican citizens aged 18 or over who are registered with the Federal Register of Voters, appear on the electoral roll (lista nominal) and have a valid voter ID card (credencial para votar) (Constitution, article 34; LGIPE, article 9). The INE issues the voter ID card at its service offices (módulos de atención ciudadana).

Where. You vote at the polling station (casilla) of the electoral section of the address on your voter ID card. If you are away from home on election day, you can vote at a special polling station (casilla especial): outside your district, but in your state, you can only vote for the proportional representation lists.

At the polling station. Polling stations are open from 8:00 to 18:00, local time, and stay open while there are voters queuing at 18:00. You show your voter ID card, the officials check that you are on the roll, and you mark the box of the party you are voting for, in secret. If you cannot read or mark the ballot, you can be helped by a person you trust.

Coalitions on the ballot. If you mark more than one party of the same coalition, the vote counts once for the coalition’s candidate and is split equally between those parties. If you mark parties that are not in the same coalition, the vote is spoilt.

Results. On election night the INE publishes preliminary results and quick counts. The official results come from the district counts, which begin on the Wednesday after the vote; the INE then allocates the proportional seats, and the Electoral Tribunal settles any challenges.

Three official INE look-up tools cover the practical side. None of them asks for more than your voter ID card or your address, and this site does not store anything you look up there.

• Your voter ID card. You need a valid voter ID card (credencial para votar) to vote. If you have lost it, moved house or it has expired, you renew it at an INE service office, by appointment, before the deadline the INE sets for the election. Voter ID card (INE)
• Your polling station. A few weeks before election day, the INE publishes the location of every polling station: with the details on your voter ID card (state and electoral section) you can see the address of yours on a map. Ubica tu casilla (INE)
• Your candidates. Once candidacies are registered (from April 2027), the INE publishes who is standing in each district, with their CV and proposals, on “Candidatas y Candidatos, Conóceles”. Conóceles (INE)

The test on this site compares your views with the parties’ positions, not with each candidate: on the federal ballot you vote for a party, and that vote also counts for the 200 proportional representation seats. If you are not sure who to vote for, here is how to compare your views with each party’s.

No vote for federal deputies. Mexicans living abroad cannot vote for the Chamber of Deputies: the law provides for voting from abroad only for the presidency, the Senate and, where state law allows it, some local offices.

Local elections. In 2027, people from some states with local elections can vote from abroad for their state’s offices, after registering with the INE. The INE explains how on its website.

The campaign lasts 60 days and ends three days before the vote. From then until election day, no campaign events or electoral propaganda are allowed (LGIPE, article 251). In the three days before the election and on election day until the polling stations in the westernmost time zones close, no one may publish or spread, by any means, the results of polls or surveys that aim to show voters’ electoral preferences (LGIPE, articles 213 and 251); doing so is a crime (General Law on Electoral Crimes, article 7). Anyone who publishes a poll or survey on electoral matters during the process must also give the full study to the INE.

The barometer on this site is not an opinion poll or a survey: it does not ask how people will vote, it publishes nothing by party and it is not representative. It only shows how much people who chose to take the test agree with each statement, by state. Even so, it is switched off from 2 to 6 June 2027, and none of its figures are published on those days. The test itself stays open.