Purpose: Personalized learning plans (PLPs) are increasing in use and USA state-level educational policies. PLPs are key components in proficiency-based learning reforms and flexible pathways to graduation. Although the theoretical and implementation literature is increasing, evidence of student outcomes is more difficult to readily identify. The purpose of this paper is to report on a comprehensive systematic literature review summarizing student outcome data for the use of PLPs. The search began in 2019 and concluded in 2020, and updated in 2023, with 330 documents, yielding just four that met inclusion criteria for this study. Design/methodology/approach: The design and methodological approach follows the conventions of a systematic literature review using Cochrane Collaboration recommendations and PRISMA reporting standards. Findings: Findings indicate of 330 documents, fewer than five met criteria for measures of student outcomes. Interestingly, the studies occur within a five-year period, reflecting four different research teams and appear predominantly in nonpeer refereed journals. Research limitations/implications: The authors discuss the importance of outcomes research for this area and identify strengths and needs for this body of literature. Although application of a broader definition of personalized learning might have enabled us to identify more studies, the generalizations of findings would be limited in proportion to the degree of vagary around operationalization. Practical implications: Identifying the outcomes in student learning associated with personalize learning plans will require agreement around operationalizing definitions. Originality/value: No review of this literature exists to date, making this work completely original. The data leads us to articulate a need for the field to better understand how to measure and report flexible practices such as a PLP.