Objectives: Accountability for reasonableness (A4R) provides a coherent theoretical framework to evaluate healthcare distributive justice as part of healthcare policy. This study aimed to analyze people’s knowledge about and attitudes toward employing A4R (including relevance of decisions, transparency, involvement of stakeholders, and revisability) in the National Health Insurance (NHI) treatment/drug reimbursement decision-making process, and to explore factors associated with the relevance of such decisions. Methods: A total of 1,140 adults aged 20 and over were randomly sampled from a nationwide population and interviewed by telephone. Multinomial logistic regression was used to examine the associations of individual characteristics, transparency, involvement of stakeholders, and revisability with the relevance of decisions. Results: Most respondents regarded A4R as essential to the NHI reimbursement decision-making process, but only few recognized how A4R was implemented. Additionally, with regard to considerations about setting healthcare priorities - (medical efficacy, disease burden, treatment/drug price), respondents’ concerns about price were associated with age, education, income, medical utilization, and their subjective perspectives about transparency and the involvement of stakeholders. Their concerns about disease burden were associated with age, income, chronic disease status, and subjective perspective about the involvement of stakeholders. Conclusions: Even though most people agree on employing A4R to support fair priority-setting in NHI’s reimbursement decision-making, a gap exists between their attitudes and knowledge. Additionally, public attitudes about the relevance of decisions are associated with socio-economic characteristics and concerns about transparency and the involvement of stakeholders. [ABSTRACT FROM AUTHOR]