Every applicant gets one. It is a tiebreaker inside a priority group, and it is worth much less than the amount of energy spent decoding it.

What the number is

A long string of letters and numbers. The Department publishes a real one as its example: B51920AF-F1C6-40EC-8E9A-3E1E50CB13BB. It is a UUID — eight characters, then three groups of four, then twelve, separated by hyphens. Thirty-six characters in total, thirty-two of them hexadecimal digits.

They sort in this order: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F. So of these two, the first one comes first:

• 5B1920AF-F1C6-40EC-8E9A-3E1E50CB13BBsorts ahead
• B51920AF-F1C6-40EC-8E9A-3E1E50CB13BBsorts behind

That is the whole of the decoding. The leading characters decide where you sit in the sort, which is why a number starting with 0 feels lucky and one starting with F does not. What they do not do is tell you whether you get in.

How it is generated

The Department has published the line of code. MySchools stores the number on each application as `lottery_id`, a `models.UUIDField` whose default is `uuid.uuid4`. Python's `uuid.uuid4()` takes no arguments, so nothing about a child — race, income, ZIP code, seat group — can reach it. A new number is generated independently for each admissions process, so a child applying to both middle school and Summer Rising has two unrelated numbers.

Why it cannot tell you your chances

Two reasons, both from the Department's own explanation.

• Priority groups outrank it entirelyEveryone in a program's priority group 1 gets offers before anyone in group 2, whatever their numbers. The random number only sorts people who are already tied.
• Your competition disappears while the match runsThe Department's example: on a list of 100 applicants your number puts you at #75, then 30 students ahead of you match to a school they ranked higher and are no longer in contention, so your real position is #45. It calls this "a fairly common occurrence."

To actually compute your odds you would need every other applicant's number and every other applicant's full ranked list. Nobody has that.

When you can see it

• Middle school, high school, Gifted and Talented grades 1-4, Summer Rising, DREAMvisible in MySchools as soon as the application is started.
• 3-K, pre-K and kindergartenhidden until after the application deadline, so that only one number is ever generated per child.
• Twins, triplets, foster siblingslink the applications in MySchools and the children share the same number, the best of theirs, plus the same choices. Linking does not guarantee the same offer; different seat groups or an audition can still split them.

The number on your waitlist is a different number

Applicants do not carry their application number onto waitlists. A new random number is issued for each waitlist a child is on. You never need to know it — the position MySchools shows you already accounts for it.

What this is a tiebreaker inside

The match itself is a deferred acceptance algorithm, the Gale-Shapley method. The State Comptroller's audit of it, report 2022-N-7 issued 24 July 2025, describes the random number as one input among four: the number itself, how the applicant ranked the programs, how many applicants are in each priority group, and how many seats there are.

The one thing worth doing with it

Nothing. List programs in true preference order, include some with average demand alongside the ones everyone wants, and ignore the number. Ranking a school lower does not reduce your chance of getting into it.

Where this came from

Checked 2 August 2026 against the Random Numbers in Admissions page at schools.nyc.gov/enrollment/enroll-grade-by-grade/how-students-get-offers-to-doe-public-schools/random-numbers-in-admissions, which is where the example number, the sort order and the Python code all come from; the Kindergarten admissions page on the same site; and Office of the State Comptroller audit 2022-N-7, "Management of the Student-School Matching Algorithm", issued 24 July 2025.