What The 90 Club™ is
The 90 Club™ is a conditional mastery rebate. On an eligible course it is included with enrollment at the posted price — there is no surcharge and, on those courses, no separate plan to choose. A small number of courses instead offer it as an optional plan; when they do, the course page and checkout say so and show the exact figures.
It is a promise to send money back after you qualify, not a checkout discount, coupon, price match, pass guarantee, score guarantee, license guarantee, or outcome guarantee. The rebate is never deducted at checkout.