Section 153.720 - Establishment and usage of masked enrollee identification numbers(a)Enrollee identification numbers. An issuer of a risk adjustment covered plan or a reinsurance-eligible plan in a State in which HHS is operating the risk adjustment or reinsurance program, as applicable, must- (1) Establish a unique masked enrollee identification number for each enrollee; and(2) Maintain the same masked enrollee identification number for an enrollee across enrollments or plans within the issuer, within the State, during a benefit year.(b)Prohibition on personally identifiable information. An issuer of a risk adjustment covered plan or a reinsurance-eligible plan in a State in which HHS is operating the risk adjustment or reinsurance program on behalf of the State, as applicable, may not-(1) Include enrollee's personally identifiable information in the masked enrollee identification number; or(2) Use the same masked enrollee identification number for different enrollees enrolled with the issuer.