Breach filing
ArchivedZOLL Services LLC: 997,097 individuals, Mar 2023.
ZOLL Services LLC reported a breach of unsecured protected health information to the HHS Office for Civil Rights on 10 March 2023. The filing records the organisation as a healthcare provider in Massachusetts and lists 997,097 individuals affected, which makes it the 5th largest of the 241 Massachusetts filings on the register and the 39th largest of the 746 filings submitted nationally in 2023. Among the 39 Massachusetts filings made in 2023 it ranks 3rd.
Individuals affected
997,097
As reported to HHS
Modelled cost (IBM 2025)
$160M
Upper bound, method shown
Rank in MA
5th
of 241 Massachusetts filings
Rank in 2023
39th
of 746 filings nationally
Section F.1 / The filing
As posted by HHS OCR
Every value below is the portal's own field for this filing, plus its rank within the register.
- Covered entity type
- Healthcare Provider
- Individuals affected
- 997,097
- Breach submission date
- 10 March 2023
- Submission year
- 2023
- Type of breach
- Hacking/IT Incident
- Location of breached information
- Network Server
- Business associate present
- No
- State
- Massachusetts (MA)
- Portal status
- listed in the HHS OCR breach portal archive
- Rank in Massachusetts by size
- 5th of 241
- Rank in 2023 nationally
- 39th of 746
- Massachusetts median filing
- 3,900 individuals
- Register id (derived)
- MA-20230310-zoll-services
Section F.2 / In context
Where this filing sits in Massachusetts and in 2023
OCR classifies the incident as a hacking or IT incident, with the breached information held in a network server. Hacking/IT Incident is the type recorded on 151 of the 241 Massachusetts filings (63%) and on 82% of all filings submitted in 2023. Network Server is the most common location in the state, appearing on 51% of Massachusetts filings.
No business associate is recorded on the filing; 37% of Massachusetts filings do involve one. At 997,097 individuals the breach is 256 times the Massachusetts median filing of 3,900 and 249 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 in the HHS OCR breach portal archive. OCR's closing summary of the case is reproduced in full below.
Massachusetts's breach notification statute (Mass. Gen. Laws ch. 93H) requires notice to affected residents as soon as practicable and without unreasonable delay. Its attorney general threshold: all breaches (AG and Office of Consumer Affairs and Business Regulation). 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 997,097 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 $160M; the 2026 edition's $192 gives $191M. Both are modelled estimates with the method shown, not costs disclosed by ZOLL Services LLC. 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.
Section F.3 / OCR closing summary
The portal's archived description, in full
Written by the Office for Civil Rights when the case was closed and reproduced verbatim from the HHS export.
The covered entity (CE), ZOLL Services, reported that it experienced a ransomware attack that affected the protected health information (PHI) of 997,097 individuals. The PHI involved included names, social security numbers, addresses, birthdates and other treatment information. The CE notified HHS, the affected individuals, and the media. In response to the breach, the CE provided complimentary credit monitoring services and implemented additional administrative, technical, and security safeguards to better protect its PHI.
Section F.5 / Modelled cost
997,097 individuals through IBM's per-record figures
Modelled cost / method shown, not a disclosed cost
Upper boundIBM 2025 customer PII, $160 per record
$160M
997,097 x $160
IBM 2026 customer PII, $192 per record
$191M
997,097 x $192
Method: individuals affected, as reported by ZOLL Services LLC to HHS, multiplied by IBM's customer-PII cost per record (Cost of a Data Breach 2025 Figure 6 and the 2026 edition). No cost has been disclosed by the entity for this filing; the figure is a planning estimate, not a fact about the breach. IBM's per-record figures come from mid-volume breaches and IBM cautions against applying them to breaches involving millions of records; the site's per-record page explains where the multiplication holds and where it breaks down.
Context: IBM's average cost of a healthcare breach is $6.64M in the 2026 report ($7.42M in 2025); the global average across all sectors was $4.44M in 2025.
Cost per record: method and limits / Healthcare breach cost, IBM 2026
Section F.6 / Notification clock
Massachusetts statute and the HIPAA rule
State notification statute
Massachusetts: Mass. Gen. Laws ch. 93H
paired with 201 CMR 17.00 data-security regulations
- Notice to individuals
- As soon as practicable and without unreasonable delay
- Attorney general threshold
- All breaches (AG and Office of Consumer Affairs and Business Regulation) (As soon as practicable and without unreasonable delay)
- Private right of action
- Yes: Chapter 93A claims, subject to a 30-day pre-suit demand letter requirement
- Penalty
- Up to $5,000 per violation; treble damages for willful violations, plus attorney fees
The HIPAA Breach Notification Rule runs alongside the state statute: notice to affected individuals and to HHS without unreasonable delay and no later than 60 days after discovery.
Section F.7 / Peer filings
Massachusetts filings closest in size
Neighbours by size rank among Massachusetts filings in 2023, topped up from other years where 2023 has too few. Filings of 10,000 or more link to their own page.
| Covered entity | Type | Individuals | Submitted | Breach type | Location | BA |
|---|---|---|---|---|---|---|
| Harvard Pilgrim Health Care | Health Plan | 2,662,337 | 24 May 2023 | |||
| Nuance Communications, Inc. | Business Associate | 1,225,054 | 15 Sep 2023 | |||
| Transformative Healthcare, on behalf of Fallon Ambulance Services | Healthcare Provider | 911,757 | 31 Dec 2023 | |||
| The University of Massachusetts Chan Medical School | Business Associate | 135,394 | 21 Aug 2023 |
Index / Companion schedules
13 HHS breach register
→Hub: every filing, by state, year and entity.
04 Biggest breaches
→Mega-breaches with primary-source cost figures.
Industry / Healthcare
→IBM 2026: $6.64M average, 13 years at #1.
Regulation / HIPAA penalties
→OCR enforcement tiers and the 60-day rule.
11 50-state laws
→Deadline, AG threshold and penalties per state.
Cost / Per record
→Where the per-record model is reliable.
Provenance
Source: U.S. Department of Health and Human Services, Office for Civil Rights, Breach Portal (breaches affecting 500 or more individuals), retrieved 2026-08-28. Public domain. Individuals affected and dates as reported by the covered entity.
Portal: ocrportal.hhs.gov breach report. Statutory basis: HITECH Act section 13402(e)(4): the Secretary must post a list of breaches of unsecured protected health information affecting 500 or more individuals. Breaches affecting fewer than 500 individuals are reported to OCR annually and are not posted, so they are not on this register. Status wording follows the portal's two tabs ("Cases Currently Under Investigation" and "Archive") as of 28 August 2026; a filing moves to the archive when OCR closes the case. Modelled costs on this site are a method applied to the reported count, using IBM Cost of a Data Breach per-record figures, and are never a cost disclosed by the entity. This row: hhs-breach-archive__2026-08-28.csv, export row 1911.
Corrections: if you represent a listed entity and the portal row has been amended, email [email protected] with the portal entry and we will re-pull the export.