State-run programs and the Private College 529 program are two different mechanisms. State-run prepaid plans are almost always limited to public in-state colleges and universities, with a conversion mechanism that lets a beneficiary who attends a private or out-of-state school receive an amount tied to the plan's own weighted-average tuition at the time of use. That conversion is what people mean by "portability": the credits are portable in value, not in identity. The Private College 529 Plan is a consortium program sponsored by about 300 private colleges. Credits purchased there guarantee tuition and mandatory fees at member schools only, with no conversion available for a beneficiary who attends elsewhere.
A state's promise about the plan varies. Some state plans carry a full faith and credit guarantee that the state itself will make good on the promised tuition. Others are actuarially funded but not guaranteed, so the plan pays what its assets support and a shortfall could reduce benefits. A small number of state prepaid programs have suspended new enrollment or been closed to new contracts over the years for exactly that reason. Before contributing to any prepaid plan, read what the plan documents say about who bears the risk if actual tuition rises faster than the plan's return.
What the credits actually cover is narrower than a savings plan. Prepaid plans generally purchase tuition and mandatory fees only. Books, supplies, equipment, and room and board are qualified higher education expenses under section 529 in general, but a prepaid plan does not usually pay them because it is not designed to. Families who choose a prepaid product commonly pair it with a 529 savings account to cover those other components.
Residency and enrollment windows are the practical gatekeepers. State-run programs almost always require the beneficiary or the account owner to be a state resident at the time of purchase, and many have annual enrollment windows rather than year-round availability. Both features are unusual among consumer investment products and worth checking before assuming a family can enroll on any given day.
Financial-aid treatment is the same as any other section 529 account. A parent-owned or student-owned 529 is reported as a parental asset on the FAFSA. A distribution is not counted at all under the Student Aid Index formula introduced by the FAFSA Simplification Act, so the pre-2024 grandparent-529 income penalty is no longer part of the calculation. For colleges that use the CSS Profile, the treatment can differ and should be checked with each institution.