['In Australia, adult immunisation coverage is primarily monitored via periodic telephone surveys that rely on self-reported immunisation status. All Australian residents are eligible for Medicare, so we examined the feasibility of using immunisation-specific Medicare Benefits Schedule (MBS) item numbers to monitor and estimate adult influenza immunisation coverage.', 'Baseline questionnaire data from 267 129 participants from the 45 and Up Study, a prospective cohort study, were linked to data containing information on individual MBS immunisation-specific items from 2006 to 2011. Temporal trends in recording of these items were examined. Self-reported influenza immunisation status obtained from a follow-up questionnaire from 27 036 participants was then compared with the MBS immunisation records.', 'From 2006 to 2011, the pattern of MBS immunisation claims was consistent with self-reported influenza immunisation trends, with annual peaks occurring from March to May. There was fair agreement between MBS immunisation records and self-reported influenza immunisation: 48.8% (95% CI 47.1, 50.4) of participants who self-reported influenza immunisation had a matching MBS record, and 79.6% (95% CI 78.8, 80.4) who reported never having influenza immunisation had no matching MBS record. However, compared with self-reported influenza vaccination for people aged ≥65 years from the 2009 Adult Immunisation Telephone Survey (74.6%), the proportion of participants aged >65 years with an MBS immunisation record was low, with an annual median of 39.3% (range 28.3%-62.1%).'] Do medicare Benefits Schedule data to monitor influenza immunisation in Australian adults?