Payment compliance of informal sector workers in Indonesia National Health Insurance: a study on ability and willingness to pay

Background: Currently, the Indonesian National Health Insurance (NHI) covers over 90 of the population. However, around 18 of the enrolees are inactive, failing to pay premiums regularly, with proportions varying across membership types. This situation could impede access to health services and influence overall enrolees health. This study seeks to assess the ability and willingness to pay, and to identify the factors influencing them among informal workers in relation to compliance and commitment to NHI premium payments. Methods: This nation-wide survey covered fifteen districts and 4,059 respondents, examining the ability to pay and willingness to pay among informal sector workers under the NHI scheme. Willingness to pay was calculated using a bidding game, while ability to pay was calculated as 5 of disposable income, using household expenditure as a proxy for income. Logistic regression was used to explore factors influencing compliance. Variables of interest included household expenditure, membership class, regional area, payment commitment, risk aversion, and out-of-pocket expenses, while control variables comprised demographic characteristics, family medical history, healthcare utilisation, and satisfaction rate. Results: The ability to pay the premium among enrolees was generally below the current premium level, except for active enrolees in the third class. While active enrolees expressed a willingness to pay about 10 more than the existing premium, inactive enrolees were only willing to pay about 50 of it. Compliance to pay the premium was influenced by non-food and tobacco expenditures, willingness to pay, risk aversion, catastrophic illness, healthcare utilization, size of household members, and patient satisfaction. Additional factors positively influencing compliance included food and non-food expenditures, NHI literacy, and enrolee class. Conclusion and recommendation: To enhance health care access, policy efforts must address the disparity between current premium levels and informal sector workers financial capacity and willingness to pay. Given constrained government budgets, cross-sector collaboration is necessary to support stable incomes for these workers. Furthermore, strategies that foster risk awareness and payment commitment, through targeted outreach and improved health insurance literacy, may enhance long-term compliance and coverage. © The Author(s) 2025.