Anyone arriving after their late teens has already missed part of the AOW build-up, because the state pension accrues across a fixed fifty-year window rather than across a working career. The size of that gap, and the tightly time-limited route for closing some of it, are what mid-career arrivals tend to discover late.
Probably not the full amount, unless you take action. AOW builds up at 2% for every year you're insured during a 50-year window that ends at your AOW pension age — currently 67 for anyone reaching it in 2026 — so the accrual clock effectively starts at 17. If you arrived at, say, 30, you've missed roughly 13 of those years, which works out to about a 26% reduction: you'd retire on around 74% of the full AOW rather than 100%, even after a full career of Dutch social insurance contributions from then on. There is a fix: SVB (the social insurance bank) lets you buy back some of those missing years through "vrijwillige inkoop" (voluntary buy-in), but the window is tight — you have to apply within 10 years of first arriving to live or work in the Netherlands, and you need to have already been insured here for at least 5 years before you can apply. Miss that 10-year window and the option closes for good, so it's worth checking mijnpensioenoverzicht.nl or contacting SVB directly well before it becomes urgent, not right before you retire.