USACO is free to enter, open to students worldwide, and starts at an accessible entry level, while its higher divisions are genuinely challenging. It is the competition that selects the United States team for the International Olympiad in Informatics (IOI). If you want to take part but are still unsure about the contest schedule, how to register, or where to find preparation resources, this guide walks you through each step.
Introduction to USACO
USACO stands for the USA Computing Olympiad, an official computer programming competition for middle and high school students, hosted in the United States. It is free, with no participation fees, and welcomes students around the world. The three regular contests are held online, so you only need to register an account and complete your contest within the allotted window. For the 2025-26 season, the final round — the US Open — moved to a proctored, in-person format at designated sites.
Contest Schedule
USACO runs three online contests during the season, and you can take part in each one. The top competitors are then invited to the US Open, the season’s championship round. The 2025-26 season ran on the following schedule:
- First contest: January 9-12, 2026
- Second contest: January 30 – February 2, 2026
- Third contest: February 20-23, 2026
- US Open (proctored, in person): March 28, 2026
Each contest window spans several days, and within it you take one continuous contest of about four to five hours. Gold and Platinum contestants who want a certified score must begin on the Saturday at 12:00 ET, when the problems are released — there is roughly a 15-minute window to start.
How to Register
1. Create an Account
Go to the official USACO website at usaco.org and click “Register for New Account” to create your account.
2. Complete Your Details and Activate the Account
Fill in the requested information to finish registering. USACO will email an account name and an initial password to the address you provide; log in on the official site to activate the account, then change your password once you are signed in.
3. Start the Contest
During an open contest window, open the contest page and click the start button. Your timer begins immediately and cannot be paused, so start only when you are ready to work straight through. Problem statements can be viewed in several languages using the selector on the problem page, including Chinese.
4. Submit Your Solutions
Write your solutions in your own programming environment — for example, an IDE such as Dev-C++ or VS Code — and submit your source file. USACO accepts C, C++, Java, and Python; C++ is recommended for the higher divisions and is the only language used at the IOI. You can resubmit as often as you like while your timer runs, and only your last submission is graded. The contest ends automatically when time runs out, or you can finish early if you reach a perfect score; just make sure you submit before the timer expires.
Competition Divisions
USACO has four divisions, in increasing order of difficulty. Every new participant starts in Bronze and moves up by earning promotions. For the 2025-26 season, Platinum competitors were reset to Gold at the start of the year — a practice USACO has said it may continue in future seasons.
- Bronze: entry level — basic programming, simple logic, and straightforward algorithms such as simulation, sorting, and brute force.
- Silver: common techniques such as greedy algorithms, binary search, prefix sums, and graph traversal (DFS).
- Gold: dynamic programming, graph theory and shortest paths, and efficient data structures such as union-find.
- Platinum: advanced modeling and algorithm design, with no fixed syllabus and no upper bound on difficulty (segment trees and advanced dynamic programming are typical).
How Promotion Works
Each contest is scored out of 1000 points, typically across three problems worth about 333.33 points each, with around ten test cases per problem. If your score clears that contest’s promotion cutoff, you move up to the next division for future contests. Cutoffs vary from contest to contest; in recent seasons the monthly contests have mostly fallen in the 650-750 range, with the US Open sometimes higher. A perfect score of 1000 earns an immediate promotion, and you may start the next division’s contest within the same window.
The Value of USACO
USACO is the qualifying competition that selects the United States team for the International Olympiad in Informatics (IOI), which USACO describes as the most prestigious international algorithmic programming competition at the high-school level. The top four competitors in the USA earn places on the IOI team. MIT Admissions’ blog lists USACO as the US qualifying competition for the IOI.
For students interested in computer science, working through the divisions builds genuine problem-solving and algorithmic skills, and a strong USACO record is a recognized signal of ability. Anyone worldwide can compete in the online contests and use the free training resources, but only pre-college students in the USA are eligible for finalist and training-camp selection and for the USA IOI and EGOI teams.
The USACO finalist training camp is hosted at Clemson University. For the 2025-26 season, the top USA competitors from the online contests were invited to the proctored US Open, which was the main basis for training-camp selection. Reaching the higher divisions is a meaningful accomplishment in its own right, whatever your longer-term academic plans.
Free USACO Preparation Materials
Scan the QR code below for free practice problems, study guides, and past contest materials to help you get started.