Background: In Aotearoa New Zealand, co-payments to see a general practitioner (GP, family doctor) or collect a prescription are payable by virtually all adults. Objective: To examine the extent to which these user co-payments are a barrier to accessing health care, focussing on inequities for indigenous Māori. Methods: Pooled data from sequential waves (years) of the New Zealand Health Survey, 2011/12 to 2018/19 were analysed. Outcomes were self-reported cost barriers to seeing a GP or collecting a prescription in the previous year. Logistic regression was used to estimate odds ratios (ORs) of barriers to care for Māori compared with non-Māori, sequentially adjusting for additional explanatory variables. Results: Pooled data included 107,231 people, 22,292 (21%) were Māori. Across all years, 22% of Māori (13% non-Māori) experienced a cost barrier to seeing a GP, and 14% of Māori (5% non-Māori) reported a cost barrier to collecting a prescription. The age- and wave-adjusted OR comparing Māori/non-Māori was 1.71 (95% confidence interval [CI]: 1.61, 1.81) for the cost barrier to primary care and 2.97 (95% CI: 2.75, 3.20) for the cost barrier to collecting prescriptions. Sociodemographics accounted for about half the inequity for both outcomes; in a fully adjusted model, age, sex, low income, and poorer underlying health were determinants of both outcomes, and deprivation was additionally associated with the cost barrier to collecting a prescription but not to seeing a GP. Conclusions: Māori experience considerable inequity in access to primary health care; evidence supports an urgent need for change to system funding to eliminate financial barriers to care.

High-income countries like Aotearoa New Zealand are grappling with inequitable access to healthcare services. Out-of-pocket payments can lead to the reduced use of appropriate healthcare services, poorer health outcomes, and catastrophic health expenses. To advance our knowledge, this systematic review asks, “What interventions aim to reduce cost barriers for health users when accessing primary healthcare in high-income countries?” The search strategy comprised three bibliographic databases (Dimensions, Embase, and Medline Web of Science). Two authors selected studies for inclusion; discrepancies were resolved by a third reviewer. All articles published in English from 2000 to May 2022 and that reported on outcomes of interventions that aimed to reduce cost barriers for health users to access primary healthcare in high-income countries were eligible for inclusion. Two blinded authors independently assessed article quality using the Critical Appraisal Skills Program. Relevant data were extracted and analyzed in a narrative synthesis. Forty-three publications involving 18,861,890 participants and 6831 practices (or physicians) met the inclusion criteria. Interventions reported in the literature included removing out-of-pocket costs, implementing nonprofit organizations and community programs, additional workforce, and alternative payment methods. Interventions that involved eliminating or reducing out-of-pocket costs substantially increased healthcare utilization. Where reported, initiatives generally found financial savings at the system level. Health system initiatives generally, but not consistently, were associated with improved access to healthcare services.