This pilot study examined the promise of a Tier 2 sixth grade intervention program for students at-risk for difficulties in mathematics. The study utilized a quasi-experimental design. The final sample included 112 students in treatment (Promoting Algebra Readiness) and 86 students in control (standard district practice) conditions. The Promoting Algebra Readiness program is composed of 93 lessons across four strands focused on key concepts and applications of fractions. Measures of mathematics achievement were collected at pretest and posttest. Feasibility and usability data indicated favorable impressions by users and strong levels of implementation fidelity. Gain scores of treatment students were significantly greater than control peers on two of four proximal measures of mathematics achievement. Positive non-significant effects were found on additional proximal and distal measures. Implications for educators delivering instruction for at-risk students in multi-tier service delivery models are discussed. [This paper was published in "Learning Disability Quarterly" v45 n4 p252-266 Nov 2022 (EJ1352984).]