Mild and circumscribed reading difficulties (MCRD) refer to relatively mild, limited, or restricted weaknesses in one or more components of reading. MCRD is used here as a descriptive, process-oriented term rather than as a diagnostic category. Contemporary classification systems do not recognize MCRD as an independent disorder; therefore, it should be differentiated from developmental dyslexia, alexia, and developmental learning disorder with impairment in reading. This paper on developmental reading difficulties has placed MCRD within the contemporary understanding of reading development, assessment, neurobiology, and intervention. The narrative literature review was based on the current as well as additional (grey) literature available on reading disorders, neurobiology, assessment, and intervention. The review suggests that MCRD may describe relatively restricted difficulties involving phonological processing, decoding, word recognition, reading automaticity, fluency, and/or comprehension, without implying a distinct diagnostic entity. This paper therefore argues that reading difficulties should be conceptualized as heterogeneous and process-driven rather than primarily through diagnostic labels. Evidence supports explicit, systematic, structured, and multi-component reading intervention, with intervention intensity and instructional targets matched to a reader’s/learner’s developmental and functional reader profile. MCRD is proposed as a descriptive educational-therapeutic formulation that directs assessment towards the specific components of reading requiring support.