(UNITED STATES) The U.S. Department of Transportation has ordered Delta Air Lines and Aeromexico to end their joint venture, giving the carriers until January 1, 2026 to unwind the partnership that has shaped a large share of U.S.–Mexico air travel for nearly a decade. In a final order issued September 8, 2025, the agency terminated its prior approvals and the antitrust immunity that allowed the airlines to set prices together, plan capacity, and share revenue across their cross‑border routes. The DOT cited market distortions tied to government actions in Mexico and said continued coordination between the two airlines would harm competition. Delta’s 20% equity stake in Aeromexico remains intact.
The joint venture, approved in 2016, capped a relationship that began as a code-share in 1994 and deepened when Delta bought a 4.2% stake in Aeromexico in 2012, later raised to 20% in 2021. By granting antitrust immunity, regulators had treated the two carriers as a single competitive unit on many U.S.–Mexico routes. Ending that protection forces Delta Air Lines and Aeromexico to act as independent competitors after the deadline, with separate pricing, schedules, and route decisions.

According to the order, the government’s decision follows nearly two years of warnings to the airlines and reflects concerns shared under both President Biden and President Trump. Regulators pointed to ongoing disputes over airport slot control and access in Mexico City and argued that continued immunity would cement advantages enjoyed by the Delta‑Aeromexico alliance while squeezing other carriers trying to compete in the same market.
Delta said it is “disappointed” with the decision and warned it “will cause significant harm to U.S. jobs, communities and consumers traveling between the U.S. and Mexico.” The company said it is reviewing the order and weighing next steps. Aeromexico has not detailed next actions, but both airlines must move quickly: they have roughly three and a half months to untangle schedules, pricing systems, and shared commercial arrangements before the January 1, 2026 cutoff.
DOT’s Order and Rationale
The Department terminated approval and antitrust immunity for the agreements under 49 U.S.C. § 41309, finding that continued coordination would not serve the public interest given competitive conditions. The agency’s core allegation is that the Mexican government “repeatedly distorted competition in the market” in ways that break the bilateral air services framework between the United States and Mexico.
The most contentious move came in 2022, when Mexico pushed airlines to shift operations from Mexico City’s busy Benito Juarez International Airport to the newer Felipe Ángeles International Airport, more than 30 miles away. U.S. officials contend that Mexican authorities “confiscated slots on spurious and unsupported grounds,” while the largest share of slots effectively stayed with Delta Air Lines and Aeromexico. That preserved their lead at the primary airport and made it harder for other U.S. carriers to keep up.
By ending the joint venture’s antitrust immunity, the DOT aims to open space for more head‑to‑head competition on fares, schedules, and connections. The agency’s final order does not force Delta to sell its ownership stake in Aeromexico, a point that matters for corporate governance and potential future coordination that falls short of joint revenue decisions. But the airlines can no longer coordinate pricing or capacity, which were the most powerful tools under the alliance.
For readers seeking the statutory basis, the government’s authority to approve or disapprove such agreements is outlined in 49 U.S.C. § 41309 on the public interest and competition. That statute is published by the U.S. Government Publishing Office and can be reviewed at the official site of the federal government: 49 U.S.C. § 41309 – Approval of agreements.
Impact on Travelers
The change won’t close routes overnight, but it will reshape how tickets are priced and sold. After January 1, 2026, passengers should expect:
- Separate fare setting: Delta Air Lines and Aeromexico will no longer align prices on shared routes. Competitive fare swings may increase.
- Less seamless scheduling: Today’s tightly timed connections built under the joint venture may loosen as each airline optimizes its own schedule.
- Changes to seat availability: Capacity choices will reflect each airline’s separate strategy, which can affect award seats and upgrade space.
- Loyalty program shifts: Reciprocal earning and redemption can continue under code‑sharing agreements, but elite benefits tied to joint venture alignment may be adjusted.
Families flying for reunions, workers with cross‑border assignments, and students moving between campuses could see more choice on some routes and fewer coordinated connections on others. People planning consular appointments or tight same‑day connections should build extra time into itineraries while new schedules settle. Corporate travel managers should review contracts for implied joint venture terms that may no longer apply in 2026.
Important: The one date that matters is January 1, 2026. Travelers with tickets beyond that date should watch for schedule changes and fare adjustments, and anyone reliant on Mexico City connections should check whether flights move between airports or change timing.
Impact on Airlines and Competition
For airlines, the split means rebuilding commercial plans. Revenue sharing, which smoothed differences between U.S. and Mexican demand patterns, will end. Each carrier will have to decide where to add or trim service based on its own network needs.
Competitors that long argued the alliance blocked their growth in Mexico City may test new schedules if they can secure viable slots and gates. But slot access remains a separate challenge tied to Mexican airport policy, not resolved solely by ending this partnership.
VisaVerge.com reports that the DOT’s move fits a wider federal effort to police airline market power, especially where airport access is limited and joint control could mute competition. According to analysis by VisaVerge.com, regulators are signaling that alliances cannot rely on immunity if governments tilt the field on which those alliances compete.
The alliance survived Aeromexico’s restructuring and Delta’s increased stake, and it delivered network reach that neither airline could easily match alone. But it also grew in a period when Mexico City’s main airport hit capacity and slot rules became more contested. The DOT’s narrative is that when one side’s government limits access or reallocates slots without fair process, pairing two major carriers across the border risks locking in an advantage that others can’t overcome.
The politics are bipartisan: the record spans both President Trump and President Biden, showing agreement on the need to protect competition. Regulators want to prevent alliances from using control of scarce airport resources to shape prices and service levels for years.
What Happens Next — Unwinding Steps
Expect a staged uncoupling. The airlines must:
- Unwind joint pricing and revenue sharing by the deadline.
- Refile schedules and capacity as separate competitors.
- Adjust sales, marketing, and distribution systems that were integrated under the joint venture.
- Notify customers, corporate clients, and travel partners of policy changes for 2026 travel.
Code‑sharing that doesn’t involve joint pricing can continue if it meets normal competition rules, which could soften the shift for travelers who rely on through‑ticketing. But the core of the alliance—coordinated fares, capacity, and revenue—will end.
Delta argues the decision will raise costs and reduce service to smaller U.S. cities that feed cross‑border routes. Consumer groups and rival carriers counter that more independent competition will push prices down and expand choice where demand is strong. Different routes may see different outcomes; the first test will come in early 2026 as airlines set summer schedules and publish fares without the joint venture’s safety net.
Practical Advice and Final Takeaways
- Travelers: Check itineraries for timing and airport changes, and build extra time into tight connections.
- Corporate travel managers: Review contracts and contingency plans for cross‑border travel in 2026.
- Airlines: Prepare operational and commercial separations, and pursue slot and gate access as independent carriers.
Summary table — Key dates and facts:
| Item | Detail |
|---|---|
| DOT final order date | September 8, 2025 |
| Unwind deadline | January 1, 2026 |
| Delta stake in Aeromexico | 20% |
| Initial joint-venture approval | 2016 |
| Delta’s initial stake (2012) | 4.2% |
| Statutory basis | 49 U.S.C. § 41309 (link) |
For now, monitor communications from Delta, Aeromexico, and the DOT as airlines file revised schedules and fares ahead of the January 1, 2026 cutoff.
This Article in a Nutshell
On September 8, 2025, the U.S. Department of Transportation terminated prior approvals and antitrust immunity for the joint venture between Delta Air Lines and Aeromexico, requiring the alliance to unwind by January 1, 2026. The DOT concluded that Mexican government actions—notably slot reallocations tied to shifting operations toward Felipe Ángeles Airport—repeatedly distorted competition and gave the alliance an unfair advantage, harming other carriers. The order forces the two airlines to stop coordinating fares, capacity and revenue, though Delta’s 20% equity stake in Aeromexico remains. Travelers can expect separate fare-setting, potentially looser connections and changes to seat availability. Airlines must refile independent schedules, disentangle commercial systems and notify customers and corporate partners before the deadline. The move reflects bipartisan regulatory concern about market power where airport access is limited, and it aims to restore head-to-head competition on U.S.–Mexico routes while leaving room for non‑coordinated code-sharing where permitted.