A registration card or similar document (such as a boarding pass) may be used to onboard participants of health services programs. A data structure may store a plurality of unique identification codes linked to data elements providing personally identifiable information of participants. A document may then be generated to include an indicium, such as a QR code and/or bar code, for indicating the unique identification code for the participant, a personal identifier and a logistics detail for a biometric event. Upon receiving the unique identification code from the document, such as at the biometric event, the data element in the data structure may then be linked to an electronic medical record of the participant.