Breach filing
ArchivedHealth Center Partners of Southern California: 337,245 individuals, Apr 2021.
Health Center Partners of Southern California reported a breach of unsecured protected health information to the HHS Office for Civil Rights on 9 April 2021. The filing records the organisation as a business associate in California and lists 337,245 individuals affected, which makes it the 35th largest of the 776 California filings on the register and the 43rd largest of the 715 filings submitted nationally in 2021. Among the 72 California filings made in 2021 it ranks 8th.
Individuals affected
337,245
As reported to HHS
Modelled cost (IBM 2025)
$54.0M
Upper bound, method shown
Rank in CA
35th
of 776 California filings
Rank in 2021
43rd
of 715 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
- Business Associate
- Individuals affected
- 337,245
- Breach submission date
- 9 April 2021
- Submission year
- 2021
- Type of breach
- Hacking/IT Incident
- Location of breached information
- Network Server
- Business associate present
- Yes
- State
- California (CA)
- Portal status
- listed in the HHS OCR breach portal archive
- Rank in California by size
- 35th of 776
- Rank in 2021 nationally
- 43rd of 715
- California median filing
- 3,553 individuals
- Register id (derived)
- CA-20210409-health-center-partners-of-southern-calif
Section F.2 / In context
Where this filing sits in California and in 2021
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 398 of the 776 California filings (51%) and on 76% of all filings submitted in 2021. Network Server appears on 43% of California filings.
A business associate is recorded as present on the filing, as it is on 33% of California filings. At 337,245 individuals the breach is 95 times the California median filing of 3,553 and 84 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.
California's breach notification statute (Cal. Civ. Code 1798.82) requires notice to affected residents within 30 calendar days of discovery (effective 1 January 2026, SB 446). Its attorney general threshold: more than 500 California residents. 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 337,245 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 $54.0M; the 2026 edition's $192 gives $64.8M. Both are modelled estimates with the method shown, not costs disclosed by Health Center Partners of Southern California. 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 business associate (BA), Health Center Partners of Southern California, reported that its vendor experienced a ransomware attack that affected the electronic protected health information (ePHI) of 337,245 individuals. The ePHI involved included names, diagnoses, Social Security numbers, medications prescribed, financial and health insurance information, and other treatment information. The BA notified HHS, affected individuals, the media, and provided substitute notice. In response to the breach, the BA implemented additional administrative, technical, and security safeguards to better protect ePHI.
Section F.5 / Modelled cost
337,245 individuals through IBM's per-record figures
Modelled cost / method shown, not a disclosed cost
Upper boundIBM 2025 customer PII, $160 per record
$54.0M
337,245 x $160
IBM 2026 customer PII, $192 per record
$64.8M
337,245 x $192
Method: individuals affected, as reported by Health Center Partners of Southern California 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
California statute and the HIPAA rule
State notification statute
California: Cal. Civ. Code 1798.82
- Notice to individuals
- Within 30 calendar days of discovery (effective 1 January 2026, SB 446)
- Attorney general threshold
- More than 500 California residents (Within 15 calendar days after notifying affected consumers)
- Private right of action
- Yes: Under CCPA Civ. Code 1798.150 for breaches from failure to maintain reasonable security; $107-$799 per consumer per incident (CPI-adjusted from $100-$750, effective Jan 2025)
- Penalty
- CCPA civil penalties of $2,663 per violation, $7,988 per intentional violation (CPI-adjusted, effective Jan 2025); CCPA private right of action for security-failure breaches
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
California filings closest in size
Neighbours by size rank among California filings in 2021, topped up from other years where 2021 has too few. Filings of 10,000 or more link to their own page.
| Covered entity | Type | Individuals | Submitted | Breach type | Location | BA |
|---|---|---|---|---|---|---|
| UC San Diego Health | Healthcare Provider | 495,949 | 8 Jun 2021 | |||
| Planned Parenthood Los Angeles | Healthcare Provider | 409,759 | 30 Nov 2021 | |||
| San Diego Family Care | Healthcare Provider | 154,513 | 18 May 2021 | |||
| LifeLong Medical Care | Healthcare Provider | 115,448 | 25 Aug 2021 |
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 3276.
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.