Boy, I don't know. We are to the point now that only Pampers Cruisers size 6 will fit. Pullups are always a possibility, but in our case, the ability for her to take them off and on herself is NOT a good thing! Plus, they are expensive.
I believe that children on Medicaid can have diapers reimbursed after age 2, but I don't know from personal experience.
My DD turns 3 tomorrow and we are not anywhere even close to dreaming about potty training yet.