New startup ideas · Gifted kids, funded by proof · Coaching and mentoring, paid per verified session

startup concept

Prepstone

Makes olympiad math coaching payable by 529 plans and donor-funded seats, per verified session

Prepstone is back-office software for math circles and olympiad training programs: it documents each coach as a qualified tutor, issues per-session invoices that satisfy 529 withdrawal rules, and runs donor-funded sponsored seats for income-qualified kids on the same verification rails, with AMC and olympiad scores plus attendance as the objective record.

Software subscription
Small business
'529 plans pay for tutoring

similar startups, last 2 years (1 all-time)

no public money matching the concept's terms

Test it before you build it

$1,500 · 4 weeks · 25 prospects

For $1,500 and 4 weeks, prove that math circle directors will prepay $500 each for 529-ready invoicing this fall, and that tax professionals will put coach eligibility in writing.

Riskiest assumption · Directors of established math circles will prepay for 529-compliant invoicing before the fall term because several of their paying parents are already asking to use 529 money, rather than treating 529 eligibility as a feature no parent has requested.

1Focus group: who and where

The founder-director of an established math circle or olympiad training program, 30-200 students, charging $300-900 per semester, in a 529-heavy state (Utah, Virginia, Nevada, New York), who is setting fall 2026 tuition right now and fielding the first parent questions about the new $20,000 529 tutoring allowance.

where to find 25 · The Math Circle Network directory at mathcircles.org (200+ US circles with named directors and contact emails); the Art of Problem Solving forums, where circle directors and olympiad coaches are active daily; the Julia Robinson Mathematics Festival host-site list, whose hosts overlap heavily with circle leadership. Filter all three for circles in Utah, Virginia, Nevada, and New York.

2Sell first, build later

A prepaid fall 2026 setup: Prepstone builds the qualification file for every coach in your program and delivers per-session, 529-withdrawal-ready invoices for your entire fall term, live before October 1, 2026, so parents can pay this semester's tuition from their 529 plan.

the ask · $500 prepaid setup, credited in full toward an $1,800 per year subscription; donor-seat rails added at no charge for the first 5 programs.

a real yes · A real yes is a paid $500 invoice with a signed one-page agreement naming the fall start date. Compliments, 'our parents would love this', requests to circle back after eligibility is settled, and unpaid trials do not count.

3Small experiments

The first one attacks the riskiest assumption; each ends with a number that says whether to run the next.

1. Fifteen director demand calls
$100 · 10 days
Email 25 directors pulled from the mathcircles.org directory and JRMF host list, using the outreach script below, and book 15 twenty-minute calls. On each call, count how many parents have asked about paying with 529 money since January, and walk through a one-page mockup of a per-session 529-ready invoice. The founder runs every call personally.
keep going if · 9 of 15 directors report 3 or more parent 529 payment questions this year, and 8 of 15 ask to see the paid setup offer
2. Prepaid fall setup close
$200 · 14 days
Put up a one-page site with the landing copy below and send the $500 prepaid fall-setup offer to all 15 called directors: coach qualification file plus per-session 529-ready invoices for their full fall term, live before October 1, 2026, credited toward an $1,800 first year. Invoice each yes the same day, payable by card or ACH.
keep going if · 4 of 15 directors pay the $500 invoice within 14 days of their call
3. Parent 529 invoice test
$300 · 14 days
With the first 2 paying directors, email their combined parent lists (target 60 parents) a real offer: fall tuition payable against a 529-withdrawal-ready invoice, itemized per session. Count parents who reply requesting the 529 invoice for their fall payment.
keep going if · 10 of the first 60 parents contacted request a 529 invoice within 10 days
4. Three written CPA opinions
$900 · 10 days
Book paid one-hour consults with 3 CPAs or EAs who specialize in 529 plans and education tax (found via the AICPA directory and my529 advisor listings). Present the exact coach documentation package (competition record, AoPS or university teaching history, program syllabus, per-session invoice format) and ask each for a written email answer: does this coach qualify as a tutor under the 2026 rules.
keep going if · 2 of 3 tax professionals state in writing that competition coaches documented this way produce 529-qualified tutoring expenses

4Collect a deposit up front

Tesla took $1,000 refundable reservations for the Model 3 and $100 for the Cybertruck before building either: the deposit is the measurement, not the revenue.

$500

per prospect, refundable

how · A prepaid design-partner setup invoiced up front, payable by card or ACH; the director signs a one-page agreement with the October 1 go-live date. Small program directors pay invoices routinely, so this reads as normal course of business, not a novelty checkout. set up: Stripe Invoicing ↗

what it reserves · One of 10 fall 2026 setup slots, go-live before the first fall session, and the $1,800 founding-member price locked for year one.

refund · Refunded in full if invoicing is not live by October 1, 2026, or if the written tax opinion does not cover that program's coaches.

target · 4 paid $500 setups from 15 director calls within 30 days

before taking money · Do not market any invoice as IRS-qualified before a written tax opinion covers the coach-qualification criteria, and route sponsored-seat donor money through an existing 501(c)(3) or SGO partner, never through Prepstone's own account.

Go: build it if

2 of 3 tax professionals confirm coach eligibility in writing, 4 or more of 15 directors pay $500, and 10 or more of 60 parents request a 529 invoice: build the fall product.

Kill: stop if

Fewer than 2 of 15 directors pay, or fewer than 5 of 60 parents want a 529 invoice, or only 0 or 1 of 3 tax professionals will put eligibility in writing: stop.

5 Scripts to run itoutreach message, landing copy, deposit terms · click to open

outreach message

Your fall term starts in a few weeks, and 2026 is the first year parents can pay you with 529 money, up to $20,000 per student for tutoring. Circles that cannot issue a qualifying invoice will lose those families to programs that can. I build the coach qualification file and per-session 529-ready invoices for your whole fall term, live before your first session, $500 credited toward year one. How many of your parents have asked about 529 this year? Can I get 20 minutes this week?

landing page

Let parents pay your math circle with 529 money this fall $500 prepaid setup: coach qualification files and per-session 529-ready invoices for your full fall term, credited toward your $1,800 first year Reserve one of 10 fall 2026 setup slots before September 20

deposit terms

Pay $500 today by card or ACH to reserve one of 10 fall 2026 setup slots. It buys your coach qualification file and per-session 529-ready invoicing, live before your first fall session and no later than October 1, 2026, credited in full against your $1,800 first-year subscription. Fully refunded if we are not live by October 1 or if our written tax opinion does not cover your coaches.

Would you run this test?

One tap. The yes-share feeds the Demand pillar of this idea's score; nobody sees who answered.

Budgets are out-of-pocket estimates for a team of one to three, US market. Size the deposit to the deal, and check the terms before taking money in a regulated line.

Scorecard

Ranked against every idea in the catalog: trend, demand and 100x potential from the corpus, competition relative to the other ideas. A generated concept has no judges or swipes yet, so its pillars use the data signals only.

Idea Score, 0-100 (partial) · raw 35.3 x 1.61

Warm

competition: more crowded than 32% of ideas · headwind x0.84

+0.0

government priorities, secondary (0 matching grants)

Trend

Is the wave forming now? 2025-26 entrants vs 2023-24, rounds since 2025, the sector's live-batch direction, the 2026 trend analyst.

Entrants 2025-26 vs 2023-24 (similar companies)74
Rounds announced 2025+ in the sector44
Sector direction (live batch)0

Demand

Does anyone want it? YC's current RFS, companies already paid for something similar, the operator judge, founders' yes-rate in decks, readers who would run the test.

YC asks for it (current RFS: idea / sector)60
Someone already pays (similar companies, recent / all-time)17

100x potential

Can it return a fund? The venture judge (double weight), market-size and moat axes, neighbours still alive, the technologist judge.

no signal yet, taken as 50

Score = 100 x cbrt(Trend x Demand x 100x) x (1 - 0.5 x crowding) + government bonus (max 5), calibrated so the 95th-percentile idea scores 90 (order never changes). A geometric mean: a weak pillar cannot be papered over. Percentiles are among the 382 ideas in the catalog; the terms matched were olympiad, math, coaching, payable, 529, plans, donor-funded, back-office.

The concept in full

What: Prepstone is back-office software for math circles and olympiad training programs: it documents each coach as a qualified tutor, issues per-session invoices that satisfy 529 withdrawal rules, and runs donor-funded sponsored seats for income-qualified kids on the same verification rails, with AMC and olympiad scores plus attendance as the objective record. Paying families cross-subsidize sponsored seats; both flows pay the program, never a parent. The kid tracks a problem-set streak and score history; donors see which milestone their seat just passed, with no named minors.
Grounded in (2025-2026 signals): The Act doubles the K-12 529 cap from $10,000 to $20,000 per child from 2026 and extends qualified expenses to tutoring by a qualified tutor, AP fees and standardized tests. Medly AI raised $8M on August 19, 2026 to expand AI tutoring, evidence that paid tutoring demand is being funded right now.
What it rides: '529 plans pay for tutoring, test prep and exams, $20,000 a year from 2026': Prepstone converts olympiad coaching into documented qualified-tutor expenses those withdrawals can legally reach.
Why now: 2026 is the first tax year the $20,000 cap and tutoring eligibility apply, and no small olympiad program has the paperwork to accept 529 money; whoever standardizes qualified-tutor documentation this school year becomes the default.
Wedge: first customer and entry point: Five established math circles in 529-heavy states: onboard their coaches, generate compliant invoices for the fall 2026 term, then switch on donor seats through a partner SGO.
Closest real companies, as the generator saw them: Excellence Learning, Tegore and Miyagi Labs sell AI tutors that replace the coach; Medly AI does the same at scale. Prepstone keeps the human coach and makes the money rails work.
Main risk: IRS defines qualified tutor narrowly enough that competition coaches without teaching credentials fall outside 529 eligibility.

Similar startups in the directory

Companies whose pitch matches most of the concept's terms (olympiad, math, coaching, payable, 529, plans, donor-funded, back-office).

Napkin Mathyc X26 · 2026 · Consumeralive
AI nutrition coach in your pocket

Public money in this direction

US federal grants and open opportunities matched to the concept's terms.

No matching grants or programs tracked; 33 startup-relevant grants exist in Consumer overall.

Other concepts in this collection

Fictional concept generated 2026-08-27 by claude-fable-5 from the collection's brief and MarkosWeb data. Treat it as a research prompt, not a plan.