Quest Diagnostics Data Breach: What Happened and What to Do

Quest Diagnostics confirmed in October 2026 that hackers accessed a system used to order lab tests and took some patient records. Here is what is known and what to do if you are a Quest patient.

1. What happened

Quest discovered unauthorized access to its Quanum Lab Services Manager and disclosed it on October 22, 2026. It notified federal law enforcement.

2. What was taken

Quest says certain patient records were accessed and some protected health information was taken. It has not said exactly what data or how many patients.

3. What it isn't

Quest told the AP the breach is not connected to the PHP vulnerability in the news the same week.

4. What to do

Watch for a breach letter from Quest. Freeze your credit at Equifax, Experian and TransUnion (free). Check medical bills and insurance Explanation of Benefits statements for visits or tests you never had.

Sources

AP reporting via AJC and WSMV (October 22, 2026); Privacy Guides breach roundup (October 30, 2026).

FAQ

How do I know if I'm affected?

Quest is still investigating. Affected patients are normally notified by mail. Be careful with emails or calls claiming to be Quest that ask for information.

Should I freeze my credit?

It's free and blocks new accounts in your name, so it's a good step after any breach that may include personal details.