Henry Ford Health System has confirmed a data breach affecting more than 18,000 of its patients.
The organization says the personal health information of 18,470 people was viewed or stolen by someone who managed to gain access to the system.
"We are very sorry this happened. We take very seriously any misuse of patient information, and we are continuing our own internal investigation to determine how this happened and to ensure no other patients are impacted," read the statement in part.
The Henry Ford Health System says they first learned of the breach on October 3, 2017.
The information that was compromised was patient name, date of birth, medical record number, provider's name, date of service, department's name, location, medical condition and health insurer.
A spokesperson for the health system says this impacts patients for 2017, across the state and possibly even out-of-state.
Impacted patients should look for a mailed notification letter, signed by their Chief Information Privacy and Security Officer.
Patients who have received a notice can call 844-327-2396.
Henry Ford Health System says it is also adjusting security in light of the breach:
"To reduce future risk of this happening again, we are strengthening our security protections for employees, all of whom will be educated about this measure in the coming weeks. In addition, we are expediting our initiatives around email retention and multi-factor authentication, which will decrease future risks to our patients and employees. To provide protection to our patients, new medical record numbers will be issued upon request."