In a statement, Harris says the lawsuit was filed and settled for $150,000 Monday in Los Angeles Superior Court, and involved letters mailed to 33,000 Medicare Supplement and Medicare Part D subscribers between April 2011 and March 2012.
In the lawsuit, Harris's office alleged Anthem violated a state law that restricts the disclosure of Social Security numbers.
Anthem spokeswoman Leslie Porras says member privacy is important and those affected were notified and offered free credit monitoring.
Porras adds there is no indication that any information from the mailings was abused and the insurer developed a new alert system for sensitive policyholder information.