IMPORTANCE Information on the associations between barriers to delivery of bariatric surgery and poor weight trajectory afterward is lacking. Estimates are needed to inform decisions by administrators and clinicians to improve care. OBJECTIVE To estimate the difference in patient-years of treatment for diabetes, hypertension, and dyslipidemia and public-payer cost between the Canadian standard and an improved bariatric surgery care pathway. DESIGN, SETTING, AND PARTICIPANTS Economic evaluation of a decision analytic model comparing the outcomes of the standard care in Canada with an improved bariatric care pathway with earlier sleeve gastrectomy delivery and better postsurgical weight trajectory. The model was informed by published clinical data (101 studies) and meta-analyses (11 studies) between January and May 2019. Participants were a hypothetical 100-patient cohort with demographic characteristics derived from a Canadian study. INTERVENTIONS Reduction of Canadian mean bariatric surgery wait time by 2.5 years following referral and improvement of patient postsurgery weight trajectory to levels observed in other countries. MAIN OUTCOMES AND MEASURES Modeling weight trajectory after sleeve gastrectomy and resolution rates for comorbidities in Canada in comparison with an improved care pathway to estimate differences in patient-years of comorbidity treatment over 10 years following referral and the associated costs. RESULTS For the 100-patient cohort (mean [SD] 88.2% [1.4%] female; mean [SD] age, 43.6 [9.2] years; mean [SD] body mass index, 49.4 [8.2]; and mean [SD] comorbidity prevalence of 50.0% [4.1%], 66.0% [3.9%], and 59.3% [4.0%] for diabetes, hypertension, and dyslipidemia, respectively) over 10 years following referral, the improved vs standard care pathway was associated with median reduction in patient-years of treatment of 324 (95% credibility interval [CrI], 249-396) for diabetes, 245 (95% CrI, 163-356) for hypertension, and 255 (95% CrI, 169-352