Second Contest of the 2025-26 Season

Our second contest of the season is available from January 30 through February 2. with contests in the gold and platinum division launching on January 31. For more information, please visit the contest page, which contains further details along with a link you can click to start your personal timer:

Note: there was a load spike towards the very end of the certified gold / platinum window that affected site responsiveness. Our sincere apologies to those affected; please know these technical issues are as frustrating for the USACO staff as they are for the participants. We are still trying to diagnose the cause of the issue to make sure it does not show up in future contests (this did not happen in the prior contest, involving a higher participant count). Any program submitted for grading by the end of your window will be graded and counted, irrespective of the length of the grading queue at that point. As this issue affected everyone in the same way, we will try to be reasonably generous when setting gold promotion cutoffs. Note also that since there were 1000+ participants in the gold and platinum contests, we will unfortunately be unable to respond to individual emails about this situation.

First Contest of the 2025-26 Season

Our first contest of the 2025-26 season has recently ended. Results are available here.

Important Note on Division Assignments

As discussed below, we will be implementing changes this year as we transition towards an updated structure for our contests and possibly also our divisions (bronze, silver, etc.). As part of these changes, we are moving all competitors currently in platinum into the gold division for the start of this competition season (the only students who will remain in platinum to begin this season are our 2025 IOI finalists as well as former finalists who performed at a comparable level in the past season). Our top competitors should therefore view their goal this season as earning promotion to platinum as well as a strong combination of certified gold and platinum scores to be invited to the final proctored contest.

For those wondering what this change means for the future, we anticipate that our contest structure will likely end up being more like the other major scientific Olympiads where accolades are independently earned on a yearly basis rather than the way things are currently set up, where a single promotion to platinum guarantees platinum standing forever. There are many details still to work out; please be patient until these are announced later. For those who have written "platinum division" on things like college applications that have already been submitted, that is of course fine, although moving forward please include the competition year (e.g., "platinum division in the 2024-25 season") to be more accurate in light of these anticipated potential changes in structure.

2025-2026 Competition Schedule Released

Our 2025-2026 competition season will be structured slightly differenly from past years, with three on-line contests in early 2026 followed by a proctored invitational championship contest. The online contests will follow the same format as past online contests, with gold and platinum results being "certified" (carrying greater weight) when a competitor starts the contest within the first 15 minute of opening (Saturday noon Eastern time during the larger 4-day contest window). Top USA competitors from the online contests will be invited to participate in the final proctored contest; detailed logistics for this are still being worked out and will be announced later. Results from the proctored contest will determine who is invited to our 2026 camp as a finalist, as well as the four individuals who will represent the USA at the 2026 EGOI (this year the EGOI is held prior to our camp, necessitating an earier selection process; the EGOI team and top EGOI prospects for future years will still be invited to our camp for training).

This year will be somewhat transitional as we gain experience with how to most effectively implement our final proctored contest. The same (bronze, silver, gold, platinum) division structure will remain in place this year for stability, but this may possibly be tweaked slightly in the future to place more emphasis on yearly results stemming from the final proctored contest.

To recap the details about "certified" contest results: In the gold and platinum divisions, problems will be first released at 12:00pm (noon) eastern time (ET) on the Saturday of the larger Friday-Monday contest timeline. Any student who begins the contest between 12:00pm and 12:15pm ET on that day will receive a certified score (treated by USACO staff as having higher potential credibility and weight than a non-certified score). Certified results are only possible in gold and platinum; the bronze and silver divisions will run as in the past, with problems available at the beginning of the Friday of the contest timeframe. In order to promote from gold to platinum, your score must be certified. In order to earn an invitation to our final proctored contest, USA-based students should have at least 2 and ideally 3 certified scores from on-line contests this season (USACO coaches will consider any exceptional situations outside these parameters on a case-by-case basis).

Excellent Results at 2025 IOI and EGOI

Congratulations to the USA team for their strong results at IOI 2025 in Bolivia: Brian Xue (silver), Alex Chen (bronze), Bing-Dong Liu (silver), and Rain Jiang (gold). Congratulations as well to Pearl Yu (bronze), Helen Law (gold), Luna Hudman (gold), and Grace Li (gold) for their outstanding results while representing the USA at 2025 European Girls Olympiad in Informatics in Germany!

2024-2025 Finalists Announced

The USACO is pleased to announce its finalists for the 2024-2025 season, all invited to participate in our training camp in late May to compete for selection for the USA teams attending the International Olympiad in Informatics and the European Girls Olympiad in Informatics.

Our Mission

The USACO supports computing education in the USA and worldwide by identifying, motivating, and training high-school computing students at all levels. We provide:

• Hundreds of hours of free on-line training resources and historical contest problems (complete with solutions) that students can use to improve their programming and computational problem-solving skills.
• On-line programming contests (four per year) for students at all levels.
• An intensive summer training camp, to which the top students in the USA are invited to further improve their skills and learn advanced material.
• The opportunity for the top four students in the USA to represent their country at the International Olympiad in Informatics (IOI), the most prestigious international algorithmic programming competition at the high-school level. We also select a team of the top four female high-school students in the USA to compete at the European Girls' Olympiad in Informatics (EGOI), a competition of similar prestige modeled after the European Girls' Mathematical Olympiad.

We are indebted to our amazing volunteer staff and to our sponsors for their support of our mission.

Your Account

2025-2026 Schedule

Jan 9-12: First Contest
Jan 30-Feb 2: Second Contest
Feb 20-23: Third Contest
For each contest, USA students
wishing to receive a certified
score in the platinum or gold
contest must start Saturday at
12:00 ET, when problems in those
divisions will be first released
(see contest details for
more detailed instructions)

Mar 28: US Open (Proctored)

May 12-18: EGOI (Italy)
May 21-30: Training Camp
Aug 9-16: IOI (Uzbekistan)