Initial algebra is a critical stage in the teaching of algebra and occurs when students are transitioning from arithmetic to algebra. Irish mathematics education at post-primary level has undergone a period of major reform beginning in 2010, which encompassed a radical change in the methods for teaching algebra. Despite this reform evidence emerged that students were struggling with algebra during their early years in post-primary school, however, no empirical based evidence of the specific content areas with which students struggled existed. This quantitative methods study aimed to establish a profile of what second year post-primary students (14 years old) in Ireland knew about algebra six years after the implementation of the reform. The evidence was collected using a standardised criterion referenced assessment known as a screener of initial algebra, which was developed and validated for use with Irish second year post-primary students. This research confirms that most students struggled with the key prerequisite content areas of fractions, decimal number magnitude, order of operations and exponents. Consequently, the algebra content items on variables, expressions and equations on the screener were not well answered by the majority which aligns with findings in previous international studies. The empirical results reported here are the first of their kind for Irish second-year post-primary students, providing valuable information for researchers and educators in Ireland as well as important evidence on students' knowledge of initial algebra in the international context, six years after curriculum reform and the introduction of new teaching approaches.