The aim of this study was to design and validate a redundant curriculum model from the perspective of elementary school teachers. The present research follows a sequential exploratory mixed-methods design of the instrumentation type. The qualitative phase was conducted using the phenomenological method and Colaizzi's content analysis approach. Data collection employed purposive sampling of the criterion-based type. Based on the theoretical saturation principle, data collection reached saturation with the 27th participant. The data collection instrument in the qualitative phase consisted of in-depth semi-structured interviews. The credibility of the findings was established through Guba and Lincoln’s criteria, and the reliability of the interviews was calculated using intra-subject agreement. The quantitative phase followed a descriptive survey design. The statistical population in this phase included teachers and curriculum planning experts who had published articles and conducted studies related to the research topic. Using purposive sampling, 220 elementary school teachers and 25 curriculum planning experts from Isfahan Province were selected. Data were collected through a researcher-developed questionnaire. To assess the validity of the designed questionnaire, content validity and construct validity methods were employed. Cronbach’s alpha coefficient was used to determine the reliability of the questionnaire, which yielded an overall reliability of 0.89. Confirmatory factor analysis and structural equation modeling were utilized for data analysis. The findings from the qualitative phase identified four main themes: factors contributing to an ineffective curriculum, characteristics of an ineffective curriculum, barriers to eliminating an ineffective curriculum, and strategies for overcoming an ineffective curriculum. Additionally, the quantitative results confirmed the validity of the proposed model from the perspective of experts.