Ciox Health LLC, d/b/a Datavant Group: 320,702 individuals, Oct 2024.

OCR classifies the incident as a hacking or IT incident, with the breached information held in email. Hacking/IT Incident is the type recorded on 94 of the 164 Arizona filings (57%) and on 83% of all filings submitted in 2024. Email appears on 26% of Arizona filings.

A business associate is recorded as present on the filing, as it is on 21% of Arizona filings. At 320,702 individuals the breach is 102 times the Arizona median filing of 3,146 and 80 times the national median of 4,000 across all 7,884 filings. It is one of 801 filings of 100,000 or more individuals.

As of 28 August 2026 the case is listed by HHS OCR under Cases Currently Under Investigation. OCR has not published a closing summary, so this page is limited to the fields on the filing itself; the archive entry that follows a closed investigation usually adds a short account of what was exposed and what the entity did afterwards.

Arizona's breach notification statute (A.R.S. 18-551, 18-552) requires notice to affected residents within 45 days after determining a breach occurred. Its attorney general threshold: more than 1,000 Arizona residents (AG and Dept. of Homeland Security). The HIPAA Breach Notification Rule ran alongside it: notice to affected individuals and to HHS without unreasonable delay and no later than 60 days after discovery, which is the clock that put this filing on the portal.

Multiplying 320,702 individuals by IBM's $160 customer-PII cost per record (Cost of a Data Breach 2025, the figure the site's calculator uses) gives a modelled $51.3M; the 2026 edition's $192 gives $61.6M. Both are modelled estimates with the method shown, not costs disclosed by Ciox Health LLC, d/b/a Datavant Group. Because the filing is above the roughly 100,000-record range in which the per-record figure is reliable, the result is an upper bound, not an estimate: fixed costs are spread across far more records at this scale.