Yep. Also, anyone entering the service before 2018 is grandfathered into the legacy/existing system, with the option to take the new system.
The new system isn't a bad deal, it's just not as good of a deal (**if you serve at least 20 years**). If you get out before 20 years, under the new plan, you still get some retirement benefit; which stands in stark contrast to the existing system where those guys that punch out before 20 yrs get nada.
The only "losers" here are guys that join in/after 2018 and end up doing a career; come to think of it though- the real losers are the guys that got out "early" within the last few years.
Along those lines if someone hypothetically doesn't see themselves doing 20+ years and would prefer government matches to contributions, is there any way they can opt into the new system?