My U.S. citizen fiancé and I broke up after filing the K-1 petition, but now we’re back together. Do we need to file a new petition?

If the petition was withdrawn or denied, you’ll likely need to file a new one.

If the petition is still pending, you might be able to update it, but you should confirm with USCIS.

Yes, you must file a new K-1 petition because the original petition is no longer valid after a breakup. You'll need to restart the process with USCIS.