In Washington, Oregon, California, and Arizona I have gotten into trouble for not having the right passes. They vary by state, area, and the time of year.
The first time in an area, I'll play dumb, and ask the ranger if I can purchase one from him. Sometimes you can, sometimes not. If you can problem solved. If you can't, but get directions on where you can go immediately to purchase one, so far I have avoided ever getting a ticket.
Sometimes it can be very confusing about which pass/permit you need, especially if you don't know exactly where you're going to be ahead of time. The lengths of the passes/permits can vary wildly too, sometimes all that might be available is a 3 day pass, other times, you may be able to get an annual pass.
I have several lifetime passes as well, but it's a guessing game where they're valid and where they're not. It might also depend on the particular ranger you run into. Where my national pass was accepted once, the next time a state pass might be required.
As near as I can tell, all this free camping only applies if you're somewhere where the rangers never find you. I have stayed many places and never seen a ranger, but it seems like any time I do, some sort of a pass/permit is required.