The medical records of 1,336 patients were endangered sometime around Dec. 19, after the worker took home documents. All of those documents have since been secured.
The records included birth dates, addresses, medical record numbers, driver's license numbers, and in some cases, Social Security numbers.
The medical center said it will pay for a year of credit-monitoring services for those affected by this incident to determine if there is irregular activity on their accounts.
The identity of the employee in question was not immediately released.
The San Bernardino County Sheriff's Department, the state Public Health Department and those whose records were involved in the breach have been notified.
If you have concerns about the security of your records, you can call the hospital at (800) 242-5181.