<sec><title>BACKGROUND</title>Our objective was to estimate the attributable health care costs associated with TB in Ontario, Canada.</sec><sec><title>METHODS</title>We conducted an incidence-based matched cohort study among individuals diagnosed with TB between April 1, 2002 to December 31, 2016. We matched exposed individuals 1:2 to unexposed individuals using hard and propensity score matching. Using phase-of-care costing, we calculated the mean attributable costs of TB, standardized to 10-day cost, for seven phases of illness: pre-diagnosis, initial treatment, continuation phase, remainder year 1, year 2, post-TB, and prior-to-death. We estimated survival-adjusted attributable mean 1-, 2-, and 5-year costs.</sec><sec><title>RESULTS</title>We matched 6,456 individuals with TB to 12,443 individuals without TB. Mean (95% CI) attributable 10-day costs was highest in the pre-death phase at $2,656 ($2,207, $3,104), followed by the initial treatment phase at $1,693 ($1,608, $1,778). Hospitalization costs were the largest cost component in each phase. The mean attributable 1-, 2-, and 5-year survival-adjusted costs were $25,586, $30,178, and $33,370, respectively.</sec><sec><title>CONCLUSION</title>Individuals with TB have higher health care costs over their lifetime (from pre-diagnosis until death) than individuals without TB.</sec>