This mixed-method study examines the impacts of sustainability standards on the livelihoods and poverty status of smallholder Robusta coffee farmers in Sumatra, Indonesia. The study utilises both qualitative and quantitative methodologies to assess whether farmer livelihoods are improved as a result of: i) initial involvement in a program audited against the Common Code for the Coffee Community (4C) standard; and ii) upgrading from 4C to the more stringent Rainforest Alliance (RA) Standard. A rigorous quantitative evaluation of one particular sustainability program in the Semendo region of South Sumatra used propensity score matching and instrumental variables to construct a viable counterfactual for a 4C / non-4C comparison, whilst the impact of RA upgrading was assessed using a randomised control trial (RCT). The results of this analysis should be interpreted as identifying the impacts from the way a particular firm has introduced sustainability standards in this specific context. In this context, the intervention consisted primarily of a series of exporter-managed farmer training activities that promoted sustainable agricultural practices. A sustainable value chain, where the exporter established a local buying station to source compliant coffee, was initiated but subsequently abandoned. As a result, these case-study reports on a common occurrence whereby certified coffee is not actually sold into end markets as certified coffee.