Though the government of Uganda has put in place a fully-fledged ministry of ICT and allowed citizens to electronically participate in policy formulation following article 37 of the constitution of Uganda, most citizens are still reluctant. This reluctance has led to limited participation and formulation of unrepresentative policies, loss of citizens’ trust in government, and defiance of formulated policies. This study’s focus was to apply the capability, opportunity, and motivation (COM-B) model to understand how citizens’ engagement behaviors toward policy formulation could be improved. The following hypotheses were tested: There is a significant influence of motivation and opportunity on capability; Capability mediates the relationship between motivation, opportunity, and engagement; and there is a significant influence of capability, opportunity, and motivation on engagement. A survey was used to collect data from 361 respondents in four regions in Uganda using a multistage and simple random sampling method. Collected data were analysed using SPSS and SEM. Study findings found a significant influence of Motivation and Opportunity on Capability; a significant direct influence of Opportunity and Capability on engagement; and a significant indirect influence of motivation on engagement through capability. Implying that Capability partially mediates the relationship between Opportunity and engagement but fully mediates the relationship between Motivation and engagement. However, Opportunity had the strongest influence on capability and engagement behaviors. This study’s contribution was in testing the applicability of the COM-B model in policy formulation in Uganda. The recommendation to policymakers is to increase opportunity since it has a stronger influence on both Capability and engagement behaviors.