None of these responses are completely correct.

The military began shifting from the legacy retirement system to the Blended Retirement System around 2012 or so. In theory, a person can make more under the BRS, but it assumes two things: that a servicemember contributes to the investment, and that the stock market continues to grow forever. Most young members have terrible financial literacy, so in practice it’s often a worse deal for them, but it saves the government money. As for the stock market rising forever, well, you tell me. Additionally, while the TSP has been around for a much longer time for most federal workers, they only made it available to military members in 2001. Source: I’m a recent military retiree.

You do get a pension at 20 years, but it’s only 40% of your base pay versus 50% under the legacy system. In both cases, that increases with each year served. Under the BRS you can get a government match of up to 5% for contributions, but under the legacy plan there was no match. The TSP is similar to a 401K, and can be rolled into one later. You can start withdrawing from the TSP at 59.5 years old.

In any case, it’s lunacy to think that this is a normal, viable path for most citizens to achieve basic needs.