Medellín Named Coalition Against Cartels Headquarters (A3C)

On October 24, 2026, Medellín was named headquarters of the Coalition Against Cartels of the Americas (Coalición contra Carteles de las Américas, or A3C), to be housed in the city’s C5I command centre, according to El Colombiano. Mayor Federico Gutiérrez and Defense Minister Jorge Eduardo Mora made the announcement during a tour of the C5I. US Deputy Secretary of War Joseph Humire joined them, per La FM.

The A3C is the coalition side of the US-led Shield of the Americas, which we covered when Medellín was first named its headquarters in August. The Shield’s own platform refers to an “Anti-Cartel Coalition of the Americas” (Semana). The outlets we read do not spell out the formal relationship between the two names, so this article treats the A3C as that coalition and says so where it matters. What is new is the concrete site, the Spanish name, and a construction timeline that outlets report differently.

What the Coalition Against Cartels headquarters in Medellín includes

• The coalition: El Colombiano says the A3C involves Colombia, the United States and 19 other countries of the hemisphere. La FM describes the initiative as US-government-led and aiming to bring together “more than 19” countries (La FM). Treat the exact member count as unsettled.
• The purpose: coordinated operations against transnational criminal networks, including drug trafficking, illegal gold mining and gold trafficking. It also covers intelligence capabilities and monitoring of financial flows for money laundering (El Colombiano).
• US agencies named: the FBI, DEA and HSI (Homeland Security Investigations). La FM says they will work with Colombia through an “Interagency and Transnational Fusion Center” inside the C5I. Colombia One notes that permanent participants have not been specified.
• Already operating: Gutiérrez said joint work with the US and other countries exists now and does not depend on the building being finished (La FM).

The C5I “Pentagon”: an earlier figure and a newer one

The facility is the Centro de Comando, Control, Comunicaciones, Cómputo, Coordinación e Inteligencia (C5I), nicknamed “el Pentágono de Medellín.” The numbers differ by outlet, but part of that looks like a matter of timing rather than a true conflict:

Figure	El Colombiano / La FM (Oct 24)	Colombia One (Oct 24)
Construction progress	44%	36%
Completion / opening	May 2027	June 2027 (per the mayor)
Cost	About COP 300,000 million	More than COP 205 billion (US$65.4 million, Colombia One’s conversion; the rate and date are not stated)

The 36%, June 2027 and COP 205 billion figures match an earlier update from the Medellín mayor’s office, which came after a 25% report and an 8% report in March 2026. They may be repeated in Colombia One’s story from that earlier release. We could not confirm that, so treat 44% as the more recent progress figure and 36% as the earlier one. The cost gap (about COP 300,000 million versus COP 205 billion) is not explained by timing and remains unreconciled.

Colombia One reports a nine-story building of more than 18,000 square metres. It lists AI and data analysis, cybersecurity, video analytics to identify people and licence plates, a data center and a rooftop vertiport for surveillance drones (Colombia One).

If the dates matter to you, wait for an official update from the Alcaldía. El Colombiano reports May 2027 as a completion target and gives no operating date. We found no Alcaldía, MinDefensa or US government release for the A3C announcement itself, so the account above rests on press reports.

What the city says it has achieved

The mayor’s office cited results for 2024–2026: 1,073 members of criminal structures captured, 46 of them ringleaders, plus the extradition of aliases “El Menor” and “El Mono.” It also cited Medellín becoming the first non-capital Colombian city with an Interpol office, and 35 foreigners captured for commercial sexual exploitation of minors, 12 of them convicted (El Colombiano). These are the city government’s own figures. La FM adds Gutiérrez’s claim that homicide rates are the lowest in four decades. We have not independently verified either claim.

What it means for visitors and expats

Nothing in the coverage points to changes in daily life, entry rules or visas. This is a coordination hub, not a deployment. As of October 25, 2026, none of the three reports mentions new checkpoints, foreign troops on city streets or travel restrictions.

Practical takeaways:

• Expect no change on arrival. Entry screening is a separate track. As of August 1, 2026, Migración Colombia had recorded 107 inadmissions in Antioquia this year over sexual-exploitation-tourism indicators (El Tiempo); see our Migración report.
• Safety advice is unchanged. The US Embassy’s warnings about drugging via dating apps still apply; see our Embassy alert coverage. For the wider US-Colombia picture, see what the US$1 billion security aid means for US travelers.
• The headquarters is not a visitor site. It is a secure government facility under construction. Do not plan a visit around it.
• Politics may follow. In July, then-president Gustavo Petro warned that state-based street violence “will only bring more violence” in reaction to the Shield of the Americas choosing Medellín (Infobae). Our August piece covers that dispute. For day-to-day risk on the street, road danger is a bigger statistical factor than many visitors expect; see Medellín traffic deaths exceed homicides.

Quick answers

What is the A3C?

The Coalición contra Carteles de las Américas, a US-backed, multi-country effort to coordinate operations and intelligence against transnational criminal networks. Medellín was named its seat on October 24, 2026.

Is the A3C the same as the Shield of the Americas?

Effectively it is the coalition arm of it. The Shield of the Americas is the US-led security-cooperation platform, and Semana describes its coalition as the “Anti-Cartel Coalition of the Americas.” Coverage in Spanish uses Escudo de las Américas for the platform and Coalición contra Carteles for the group. The sources we read do not define the exact institutional relationship, so check official announcements if the distinction matters.

Is the C5I finished?

No. The latest report puts it at 44% complete (El Colombiano / La FM), versus an earlier 36% figure from the mayor’s office, with a target of May or June 2027.

Does the A3C change travel to Medellín?

Not according to anything announced so far.

The bottom line

As of October 25, 2026, Medellín has a coalition name, a named US agency lineup and a building under construction. Costs and the opening date are still not settled. We will update when the mayor’s office publishes an official progress figure.