NASCO

Disclosed Oct 10, 20231,744,655 affectedConfirmed

The business associate (BA), NASCO, reported that a software application exposed the protected health information (PHI) of 1,744,655 individuals. The PHI involved included names, dates of birth, addresses, Social Security numbers, diagnoses, claims and health insurance information, and other treatment information. The BA notified HHS, the affected individuals, the media, and provided substitute notice. In response to the breach, the BA provided complimentary credit monitoring services and implemented additional administrative, technical, and security safeguards to better protect PHI.

What is known

People affected	1,744,655 (as reported to HHS)
Disclosed	Oct 10, 2023
Discovered	Jul 12, 2023
Happened	May 30, 2023
Attack	Hacking
Data exposed	NamesHealth
Sector	Healthcare · US
Status	Confirmed

Sources

Official noticeoag.ca.gov

California Attorney General breach notice: NASCO

Official noticeatg.wa.gov

Washington Attorney General breach notice: NASCO

Official noticejustice.oregon.gov

Oregon DOJ breach notice: NASCO

Official noticeago.vermont.gov

Vermont Attorney General: 2024-01-08 NASCO Data Breach Notice to Consumers

Official noticeago.vermont.gov

Vermont Attorney General: 2023-10-27 NASCO Data Breach Notice to Consumers

Official noticeocrportal.hhs.gov

HHS OCR breach report (archive, resolved): NASCO (Business Associate, GA)

Notices filed

TotalOct 10, 2023

HHS archive1,744,655 people

Residents of CAOct 27, 2023

California AGCount not stated

Residents of WAOct 27, 2023

Washington AG12,986 people

Residents of OROct 27, 2023

Oregon DOJ804,862 people

Residents of VTOct 27, 2023

Vermont AGCount not stated

Residents of VTJan 8, 2024

Vermont AGCount not stated

Residents of CAJan 10, 2024

California AGCount not stated

History of this record

data_types2026-09-25

[] to ["names","health"]by backfillSource

records_basis2026-09-25

empty to hhsby backfillSource

records2026-09-25

empty to 1744655by backfillSource

disclosed2026-09-25

2023-10-27 to 2023-10-10by backfillSource

summary2026-09-25

empty to The business associate (BA), NASCO, reported that a software application exposed the protected health information (PHI) of 1,744,655 individuals. The PHI involved included names, dates of birth, addresses, Social Security numbers, diagnosesby backfillSource

source2026-09-25

empty to https://ago.vermont.gov/document/2023-10-27-nasco-data-breach-notice-consumersby backfillSource

source2026-09-25

empty to https://ago.vermont.gov/document/2024-01-08-nasco-data-breach-notice-consumersby backfillSource

sector2026-09-25

other to healthby backfillSource

attack2026-09-25

unknown to hackingby backfillSource

discovered2026-09-25

empty to 2023-07-12by backfillSource

disclosed2026-09-25

2024-01-10 to 2023-10-27by backfillSource

Added2026-09-25

First recordedby backfillSource

First seen 2026-09-25 (California AG), confirmed by California AG. Record counts are as reported. Not legal advice.

Everything about NASCO