Background:Missed clinic appointments negatively impact clinic patient flow and health outcomes of people living with HIV (PLHIV).PLHIV likelihood of missing clinic appointments is associated with direct and indirect expenditures made while accessing HIV care.The objective of this study was to examine the relationship between out-of-pocket (OOP) health expenditures and the likelihood of missing appointments.Method:Totally 618 PLHIV older than 18 years attending two HIV care and treatment centres (CTC) in Northern Tanzania were enrolled in the study.Clinic attendance and clinical characteristics were abstracted from medical records.Information on OOP health expenditures,demographics,and socio-economic factors were self-reported by the participants.We used a hurdle model.The first part of the hurdle model assessed the marginal effect of a one Tanzanian Shillings (TZS) increase in OOP health expenditure on the probability of having a missed appointment and the second part assessed the probability of having missed appointments for those who had missed an appointment over the study period.Results:Among these 618 participants,242 (39％) had at least one missed clinic appointment in the past year.OOP expenditure was not significantly associated with the number of missed clinic appointments.The median amount of OOP paid was 5100 TZS per visit,about 7％ of the median monthly income.Participants who were separated from their partners (adjusted odds ratio[AOR]=1.83,95％ confidence interval[CI]:1.11-8.03) and those aged above 50 years (AOR =2.85,95％ CI:1.01-8.03) were significantly associated with missing an appointment.For those who had at least one missed appointment over the study period,the probability of missing a clinic appointment was significantly associated with seeking care in a public CTC (P =0.49,95％ CI:0.88-0.09) and aged between ＞ 25-35 years (P =0.90,95％ CI:0.11-1.69).Conclusion:Interventions focused on improving compliance to clinic appointments should target public CTCs,PLHIV aged between ＞ 25-35 years,above 50 years of age and those who are separated from their partners.