Social protection has expanded unevenly across Africa because of variations in both the initial adoption of programmes and their subsequent ‘institutionalisation’ through government-funded expansions in coverage. The case of Zambia illustrates how policy coalitions promoting the institutionalisation of social protection compete with other claimants over prioritisation in public spending. Even when faced with competitive elections, incumbent governments may prioritise other programmes over social protection. In Zambia, the incumbent government announced and budgeted for a massive government-funded expansion of social protection but failed to allocate the necessary funding – with the result that benefits were not paid to registered beneficiaries. If ‘institutionalisation’ is understood as entailing the political irreversibility of expansion, then the rhetoric of institutionalisation belied the reality (for several years) of retrenchment. The weakened policy coalition supporting social protection was unable to prevent government defunding as scarce government resources were allocated to competing programmes.