Quantum Health Data Breach: What Happened and What You Should Do
Quantum Health disclosed a data breach affecting an unconfirmed number of people. Here's what is currently known about the incident, what information may have been exposed, and steps you can consider taking.
- Company
- Quantum Health
- People affected
- Undisclosed (2,360 VT)
Quantum Health has not published a national total in the sources reviewed. Vermont's table lists 2,360 Vermont residents (October 28, 2026); that is a Vermont-only count, not a national total.
- Incident date
- May 29 – June 1, 2026
- Discovered
- June 1, 2026
- Disclosed
- July 31, 2026
- Information exposed
- Name · possibly insurance information, health information, date of birth, email address, physical address, phone number, social security number
- Status
- Notification underway
Notification letters mailed from July 31, 2026, with complimentary credit monitoring, dark web monitoring, and identity theft restoration; call center (844) 958-8913.
What happened in the Quantum Health breach?
How the attacker got in
A Quantum Health user responded to a vishing call on May 29, 2026, which led to unauthorized access to its IT network; files were accessed and acquired between May 29 and June 1, 2026.
Reports conflict
Timeline of what is known
- 01May 29 – June 1, 2026Unauthorized access
- 02June 1, 2026Breach discovered
- 03July 31, 2026Breach disclosed publicly
- 04July 31, 2026 onwardAffected individuals notified
Dates come from the sources listed at the bottom of this page. Separate events are kept separate; where a date has not been disclosed, it says so.
What information was exposed?
The categories below come from Quantum Health's disclosure and the sources listed on this page. Each is labeled by what the evidence supports. Categories not mentioned in any source are not listed, even if they are common in similar breaches.
Name
Name (Quantum Health notice).
Insurance information
Health insurance policy number and claims or benefits information (Quantum Health notice).
Health information
Medical and treatment information, diagnoses, prescriptions, provider names, and dates of service (Quantum Health notice; Vermont AG table lists health records).
Date of birth
Date of birth (Quantum Health notice).
Email address
Email address (Quantum Health notice).
Physical address
Mailing address (Quantum Health notice).
Phone number
Phone number (Quantum Health notice).
Social Security number
Quantum Health says it could not rule out that Social Security numbers were involved; Vermont's table lists Social Security numbers.
Why this information matters
The risks below are the ones associated with the categories of information involved in this breach. This describes how exposed information can be used in general. It does not state that any of this has happened with data from this incident.
Information from one breach can sometimes be combined with information from other breaches or public sources. A name and email address on their own are limited. Paired with a date of birth from one leak and an address from a people-search site, they become enough to answer a security question or make a scam call sound informed.
Whether the data from this breach has been sold, shared, or used is not known unless a source on this page says so. Where that is documented, it appears in the "What happened" section above.
If you were affected, consider doing these things now
Practical steps for this breach, in rough order of priority. None of these require buying anything. Monitoring services, including ours, are one option among several.
- 01Activate the complimentary identity monitoring using the code in your letter before the deadline it gives.
- 02Consider a free credit freeze with Equifax, Experian, and TransUnion; it blocks new accounts in your name and is free to place and lift.
- 03Request an IRS Identity Protection PIN to help stop someone else from filing a tax return with your Social Security number.
- 04Review explanation of benefits statements from your health plan for care, prescriptions, or claims you did not receive.
- 05Be wary of phone calls claiming to be from Quantum Health, your health plan, or your employer's benefits team; this incident began with a vishing call. Call back only on (844) 958-8913 or a number from your plan card.
AI Protection
Monitoring, alerts, and recovery help for what comes after a breach.
A breach puts information you can't take back into circulation. AI Protection watches for it being misused, alerts you when something changes, and helps you recover if something goes wrong. It cannot undo the breach or retrieve data an attacker already holds.
How one breach can contribute to a larger exposure footprint
A possible risk pattern, not a description of this incident. Each step is something that can happen after a breach. Nothing here states that it has happened with data from this incident.
Illustrative pattern- Step 1
One breach
A single company's records are accessed without authorization.
- Step 2
Personal information is exposed
Some categories can be changed afterward. Others, like a name or date of birth, can't.
- Step 3
It may remain accessible
Copies of breached data can persist well beyond the original incident.
- Step 4
Sources can be combined
Fragments from different breaches and public sources may be assembled into a fuller profile.
- Step 5
More targeted attempts
A fuller profile can make fraud, impersonation, phishing, or social engineering attempts more convincing.
A breach is an event. Exposure can last longer.
A password can be reset and a card reissued. Some information can't be replaced, and that is the part that stays useful to someone attempting fraud later. This does not mean fraud will occur. It means the risk does not close when the news cycle does.
Involved in this breach and hard to change
None of the categories reported in this breach are in the hard-to-change group. Changeable items like passwords and account numbers should still be addressed.
What Quantum Health has done so far
Only actions the company has announced or that are documented in the sources below. If something you'd expect to see isn't here, it hasn't been announced as of the last update.
Sources
Primary sources first: company disclosures, regulator and attorney general filings, SEC filings, court documents. News reporting is listed as secondary. Where reports conflict, the conflict is noted in the "What happened" section rather than resolved silently.
Last updated October 29, 2026 · First published October 29, 2026
Questions about the Quantum Health breach
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