Micronutrient powders (MNP) are recommended by the World Health Organization as an effective intervention to address anaemia in children. A formative process evaluation was conducted to assess the viability of a model using free vouchers in two districts of Mozambique to deliver MNP and motivate adherence to recommendations regarding its use. The evaluation consisted of (a) an examination of programme outcomes using a cross‐sectional survey among caregivers of children 6–23 months (n = 1,028) and (b) an ethnographic study to investigate delivery experiences and MNP use from caregiver perspectives (n = 59), programme managers (n = 17), and programme implementers (n = 168). Using a mixed methods approach allowed exploration of unexpected programme outcomes and triangulation of findings. The survey revealed that receiving a voucher was the main implementation bottleneck. Although few caregivers received vouchers (11.5%, CI [9.7, 13.6]), one‐fourth received MNP by bypassing the voucher system (26.3%, CI [23.6, 29.0]). Caregivers' narratives indicated that caregivers were motivated to redeem vouchers but encountered obstacles, including not knowing where or how to redeem them or finding MNP were not available at the shop. Observing these challenges, many programme implementers redeemed vouchers and distributed MNP to caregivers. Virtually, all caregivers who received MNP reported ever feeding it to their child. This study's findings are consistent with other studies across a range of contexts suggesting that although programmes are generally effective in motivating initial use, more attention is required to improve access to MNP and support continued use.