BACKGROUND: The COVID-19 pandemic exposed significant limitations in health systems worldwide and emphasized the need for updated National Health Policies, Strategies, and Plans (NHPSPs). This study aimed to evaluate the NHPSPs of Organization for Economic Cooperation and Development (OECD) and BRICS (Brazil, Russia, India, China, and South Africa) countries before and after the COVID-19 pandemic. Specifically, it explored each country's commitment to strengthening health systems to address health threats and analyzed the specific changes made. METHODS: NHPSP documents from the WHO document repository and official governmental websites were systematically searched. Data were extracted using a standardized template. A coding framework was inductively developed to sort qualitative texts into categories, with frequencies calculated and weighting evaluated, followed by organizing underlying content into subthemes. RESULTS: Out of 154 documents initially identified, 36 met the screening criteria, covering 14 OECD and 3 BRICS countries. The most predominant theme was prevention (88.9% pre-pandemic, 99.4% post-pandemic), which was addressed as a primary theme in 26 included NHPSPs. After the COVID-19 pandemic, 6 out of 14 analyzed themes saw higher occurrences, among which infection prevention and control (22.2-50.0%) and resilience to health crisis (22.2-44.4%) increased most significantly. Themes mainstreamed in post-pandemic NHPSPs included prevention (94.4%), health research and technology (61.1%), and One Health (66.7%). Primary healthcare emerged as the most concerned subtheme under prevention. Notably, OECD countries displayed more increased occurrences of themes (13 out of 14) or increased emphasis on themes with similar occurrences before and after COVID-19, while BRICS countries only differed in infection control. Additionally, OECD and BRICS countries varied in their subthemes and specific actions under similar primary themes. CONCLUSIONS: COVID-19 exposed vulnerabilities in many countries' health systems, highlighting the need to build resilient health infrastructures through the optimization of NHPSPs. However, only about half of the OECD and BRICS countries have implemented new NHPSPs since the pandemic. Our findings highlight the critical need for global health system reforms and offer actionable recommendations for other countries in formulating their NHPSPs.