What is maintenance in ABA?
Maintenance is the persistence of a learned skill after active teaching ends - the behavior continuing under the thinner, less structured reinforcement that everyday life actually provides.
Mastery on the day of teaching is the easy part; the real question is whether the skill is still there in a month with nobody running trials. Maintenance names that durability, and programs treat it as an outcome to engineer rather than hope for.
The main engineering tool is schedule thinning. Skills are acquired under rich reinforcement - every correct response paying off - but everyday environments pay far less often. Gradually stretching the schedule during teaching, and shifting from contrived reinforcers toward natural ones, prepares the behavior for the economy it will actually live in.
Maintenance is verified, not assumed, through probes: periodic checks of previously mastered targets without prompting or re-teaching. Well-organized programs cycle mastered targets through these checks on a schedule, so a skill that starts slipping is caught while a brief booster still fixes it.
Maintenance and generalization are siblings and get planned together - one is persistence across time, the other spread across settings, people, and materials. A skill that maintains only in the therapy room, or generalizes but fades by summer, has half the job done.
For families and funders, maintenance data is the point of the whole exercise: it is the evidence that teaching produced lasting change rather than performance that lived and died with the session structure. That is why mastered-target probes belong in the ongoing dataset, not in a drawer.