Among the 17 United Nations Sustainable Development Goals (SDGs), the fourth one is about ensuring "inclusive and equitable quality education" and promoting "lifelong learning opportunities for all". This goal (SDG 4) is subdivided into 10 targets, the sixth of which concerns youth and adult literacy and numeracy. This article examines the current discursive landscape around SDG target 4.6, to determine the extent to which it reflects the lifelong learning perspective guiding the Education 2030 "Framework for Action". SDG target 4.6 envisages a minimum proficiency level in literacy and numeracy which is equivalent to the level achieved upon successful completion of basic education. The author's analysis unpacks "lifelong literacy", and discerns three closely interrelated dimensions, namely (1) literacy as a lifelong learning process; (2) literacy as a life-wide process; and (3) literacy as part of sector-wide reforms towards lifelong learning systems. Although available documentary evidence is still limited, the author identifies a number of broad trends, many of which do not give cause for optimism. She argues that an expanded vision of literacy has not yet taken hold. There is still a long way to go before literacy (and numeracy) are tackled from a lifelong learning perspective, which would potentially have a transformative effect on the achievement of the SDGs.