Data breach

Marathon Health

Indianapolis, United States3 sources

NotifiedMarathon Health notified the California Attorney General of a data breach on 29 Oct 2026. The cause was not stated.

See it on the live map Am I affected?

Indianapolis, United States. Placed at the city in the organisation's breach notice address.

Sector: Healthcare
Confirmed: 5.7M people
First reported: 29 Oct 2026
Latest source: 30 Oct 2026

What is known

Confirmed

5,684,735 people

As stated in the notice.

Claimed

No claimed figure

Data involved

Name of individualAddressSocial Security Number InformationMedical InformationHealth Insurance InformationDate of BirthSocial Security NumbersHealth Records

Cause

Cause not statedDiscovered 50 days before the notice

Attack: 24 Aug 2026
Discovered: 9 Sept 2026
Disclosed: 29 Oct 2026
First seen by Black Shard: 9 Nov 2026

Filings

Sources

Status timeline

29 Oct 2026
California Attorney General, primary source
29 Oct 2026
Status: notified
30 Oct 2026
Vermont Attorney General, primary source
30 Oct 2026
Texas Attorney General, primary source

What to do

If you have an account, change that password, and anywhere you reused it.
Turn on two-factor authentication, ideally an authenticator app or passkey, not SMS.
Expect phishing that uses your real details. Do not click links in messages about this incident; go to the company's site directly.
If payment cards were involved, watch statements and ask your bank for a new card.
If government ID or social security numbers were involved, consider a credit freeze.

Talk to our team 24/7 incident line: 1800 370 270

How sure we are

That it happened as stated 100%

The place 70%

3 independent sources. Placed at the city in the organisation's breach notice address.

Not known yet

Who did it

Update log

9 Nov 2026First seen.

Under attack? Call the incident line.

Black Shard's team can check your exposure, take a fix off your plate or step in on a live incident.

Talk to our team Breach response

24/7 incident line1800 370 270Call first, then work through the first-hour steps.