Troughton said the company believed the letters complied with state and federal privacy and health practice laws. She said Blue Cross "highly values the trust of its members and understands the personal relationship members have with their physicians."
Sending applications to physicians for review is an important tool, Troughton said, to "ensure that it mirrors what is reflected in the physician's notes for that member."
But privacy experts said that may violate privacy laws.
"They don't have a right to contact someone that you hired and you employed to take care of your health and to release data about you without your permission," said Deborah Peel, a Texas physician who founded Patient Privacy Rights, a nonprofit advocacy organization. "What's the point of paying for insurance if they are going to look for every reason to deny what you think you paid for, which is access to services to help you?"
Jamie Court, president of the Foundation for Taxpayer and Consumer Rights, said information exchange also might violate state laws aimed at ensuring that physicians do not allow financial considerations to interfere with medical judgments.
"The real issue here is the doctor acting as a double agent," Court said.
Other large health insurers, including UnitedHealth Group Inc. -- which operates PacifiCare in California -- Blue Shield of California and Health Net Inc., said Tuesday that they did ask doctors to look for or alert them to possible preexisting medical conditions.
Margita Thompson, a spokeswoman for Health Net, said the company asks physicians for medical records when it suspects patients may have omitted preexisting conditions on applications.
"But the doctor is not asked to review the records at all," she said. "And we do not send the doctor a copy of the application for his review."
Girion reported from Los Angeles and Rau from Sacramento. Times staff writer Marc Lifsher in Sacramento contributed to this report.