Have health insurers been systematically cheating patients and doctors of fair reimbursement for medical services? That is the disturbing possibility raised by an investigation of the industry’s arcane procedures for calculating “reasonable and customary” rates.

The investigation, by the New York State attorney general, Andrew Cuomo, and his staff, suggests that these procedures  used by major insurance companies to determine what they will pay when patients visit a doctor who is not in the company’s network  may be rigged to shortchange the beneficiaries.

When patients visit an out-of-network doctor, insurers typically agree to pay 80 percent of the reasonable and customary rate charged by doctors in the same geographic area. The patient is stuck with the rest, and as any patient knows, that rate always seems to fall short of what their own doctor is charging. If the attorney general’s investigators are right, we can understand why.

The numbers are mainly compiled by an obscure company known as Ingenix, which  as it turns out  is owned by UnitedHealth Group, one of the nation’s largest health insurers. Ingenix collects billing information from UnitedHealth and other health care payers to compile a database that is then used by the insurers to determine out-of-network reimbursement rates.