Managed Care of North America
Disclosed May 26, 20233 years ago8,923,662 affectedConfirmed
LockBit ransomware attack on MCNA Dental exposes data of 8.9 million people
Dental insurer MCNA, which serves Medicaid and CHIP members, became aware of unauthorized activity on March 6, 2023 and found that an attacker had viewed and copied data from late February. Its Maine filing put the total at more than 8.9 million people; LockBit claimed the attack and leaked data after a ransom was refused.
What is known
| People affected | 8,923,662 (as reported by the organization) |
|---|---|
| Disclosed | May 26, 2023 |
| Discovered | Mar 6, 2023 |
| Happened | Feb 26, 2023 |
| Attack | Ransomware |
| Data exposed | Names, Addresses, Dates of birth, Phone numbers, Emails, Social Security numbers, Government IDs, Health, Insurance, Financial |
| Sector | Insurance · US |
| Status | Confirmed |
Sources
| Source | |
|---|---|
| California Attorney General breach notice: Managed Care of North Americaoag.ca.gov · Official notice | Official notice |
| Washington Attorney General breach notice: Managed Care of North Americaatg.wa.gov · Official notice | Official notice |
| Oregon DOJ breach notice: Managed Care of North Americajustice.oregon.gov · Official notice | Official notice |
| California AG data breach notice: Managed Care of North America, Inc.oag.ca.gov · Regulator | Regulator |
| Ransomware attack on US dental insurance giant exposes data of 9 million patientstechcrunch.com · News | News |
| Vermont Attorney General: 2023-05-26 Managed Care of North America Data Breach Notice to Consumersago.vermont.gov · Official notice | Official notice |
| Indiana Attorney General 2023 data breach report: Managed Care of North Americain.gov · Official notice | Official notice |
| HHS OCR breach report (archive, resolved): Managed Care of North America (Business Associate, GA)ocrportal.hhs.gov · Official notice | Official notice |
Notices filed
| Where | Filed | People |
|---|---|---|
| California AGresidents of CA | May 26, 2023 | |
| Washington AGresidents of WA | May 26, 2023 | 13,823 |
| Oregon DOJresidents of OR | May 26, 2023 | 8,923,662 |
| Researchtotal | May 26, 2023 | 8,900,000 |
| Vermont AGresidents of VT | May 26, 2023 | |
| Indiana AGresidents of IN | May 26, 2023 | 7,444 |
| HHS archivetotal | May 26, 2023 | 8,627,242 |
History of this record
- 2026-09-25 · source: empty to https://ocrportal.hhs.gov/ocr/breach/breach_report.jsf · backfill source
- 2026-09-25 · records: 8900000 to 8923662 · backfill source
- 2026-09-25 · source: empty to https://ago.vermont.gov/document/2023-05-26-managed-care-north-america-data-breach-notice-consumers · backfill source
- 2026-09-25 · sector: health to insurance · seed source
- 2026-09-25 · attack: hacking to ransomware · seed source
- 2026-09-25 · data_types: [] to ["names","addresses","dob","phone","emails","ssn","government-id","health","insurance","financial"] · seed source
- 2026-09-25 · records_basis: empty to organization · seed source
- 2026-09-25 · records: empty to 8900000 · seed source
- 2026-09-25 · summary: empty to Dental insurer MCNA, which serves Medicaid and CHIP members, became aware of unauthorized activity on March 6, 2023 and found that an attacker had viewed and copied data from late February. Its Maine filing put the total at more than 8.9 mi · seed source
- 2026-09-25 · title: empty to LockBit ransomware attack on MCNA Dental exposes data of 8.9 million people · seed source
- 2026-09-25 · attack: unknown to hacking · backfill source
- 2026-09-25 · discovered: empty to 2023-03-06 · backfill source
- 2026-09-25 · added · backfill source
First seen 2026-09-25 (California AG), confirmed by California AG. Record counts are as reported. Not legal advice.