Do you get any benefits when you get out of the AF after being enlisted for 4 years? If not, what insurance options are available for the enlisted that are now out?
If you are honorably discharged and were deployed at some point, then you'd qualify for VA benefits including healthcare. But that's only for you, not any dependents. This is a questionnaire to determine eligibility of VA benefits.
You can also get transitional coverage from TriCare, the military insurance provider. Details on that are here. You can get another few years of coverage for a couple thousand dollars a quarter.
The other option of course is to get insurance through any new job that you pickup after getting out.
An AF member getting out after four years would also have the GI Bill, which they could use to go to school if they liked.
Other than that there aren't many benefits for four year enlistees. You have to do the full 20 to get all the retirement benefits.