In England, pupils aged 16 take the General Certificate of Secondary Education (GCSE) examinations for a range of subjects. The current assessment models for GCSE include a two-tier structure for some subjects and a non-tier model for the others. The tiered subjects have a higher tier designed for high achieving pupils and a lower tier for low achieving pupils. The higher tier paper is targeted at grades A*-D (with A* the highest grade available), while the lower tier paper at grades C-G (with G the lowest grade). The UK government has proposed a comprehensive reform of GCSEs. It suggested that, with tiered papers, pupils are forced to choose between higher and lower tier papers, which will place a cap on the ambition of those entering for the lower tier. The government therefore suggests avoiding tiering in the reformed GCSEs when possible. This paper discusses the technical and equity issues with the use of tiered examinations in current GCSEs and reviews potential alternative assessment approaches for effective differentiation between pupils for the reformed GCSEs.