I washed and dried my passport by mistake, do I need a new one?

The chip should still work - and you can easily test it using any phone which has NFC reader. However there may be other marks - which are only visible in UV light - which could be damaged, and thus make your passport not acceptable for travel.

Considering the vagueness of "still readable", and considering that you're flying to USA, I'd say it is definitely worth investing in a replacement passport. With the current attitude of our new government coming in with a washed passport is basically asking for a trouble. And if you're turned back, your saved money won't be much of saving.

But if you insist of using your old passport, you need to check it with UV light against an undamaged passport issued in or around the same year (as the marks might change). If yours look much different, don't use it.

I left my US passport in a pants pocket in the washing machine about nine years ago, the night before an international trip. My dear mother found it and carefully dried it page by page. It came out looking almost good as new, and very clean. I've been travelling on it ever since, with no issues. Mom says if you are going to wash your passport, use cold water & gentle cycle!

Seriously though, don't wash your passport. You might not be as lucky as I was.

Other answers are wrong.

Your passport is damaged, and regardless whether the chip works, you need to get a new. Now, depending on the conditions of the passport and the person checking it, you may have problems.

If your passport is not electronic and it has no chip, it is probably still good for your next travel if all text are still clearly legible. However, I suggest that you change it as soon as possible after you return.

But you passport is electronic, so you might run into problems because the chips might be damaged. You should apply for a new passport ASAP. As long as the US visa in your old passport is still in good shape, you should encounter no problems. Just present both passports to border inspection.

Personally, I have also did something similar, but much less serious - I soaked my passport (non-electronic!) in oil and had to wipe the oil on the surface off. Later, it dried, and the state emblem on my passport was not clearly visible anymore. However, obviously all my visas and my identity page were fine. However, my passport was going to expire in a year, so I didn't get a new one.

Last year I got a new, electronic passport, and have been keeping it carefully (so as not to soak it in anything). My US visa is still in my oil soaked passport, and I had no problems travelling (with both passports).