The Galaxy Z Fold 5 was the last model in the series to lack an anti-dust rating. It was IPX8-rated, while the sequels have an IP48 rating. So if you've held on to your Fold 5 for more than two years, even without a protective case, congratulations are in order.
Apart from being the last without an IP48 rating, the Galaxy Z Fold 5 was also the last in the series to offer support for "only" four major Android OS upgrades. Samsung will support the Fold 6 and the Fold 7 with seven major OS updates.
So where does that leave you in terms of new firmware? Well, the Galaxy Z Fold 5 shipped with Android 13 and has received timely updates so far. The most recent firmware was Android 16 and One UI 8.0, which went live in September.
The Galaxy Z Fold 5 will also receive One UI 8.5 next year, but because the 8.5 update is also based on Android 16, it won't count as a major release.
With that being said, the last major OS upgrade your Galaxy Z Fold 5 will receive is Android 17, possibly at the end of 2026 or sometime in 2027.
All this is to say that, if you want to continue using your Galaxy Z Fold 5 for a while longer, you don't have to worry about firmware support just yet. And even after your phone will no longer be eligible for Android OS updates, you will still receive quarterly security patches for one more year.
On the other hand, as is usually the case with aging phones, the longer you wait, the less money your phone will be worth. So if you plan on using the trade-in program to upgrade to a newer Fold, you may want to check out the current offers and see how they hold up at present.