Lumbar puncture (LP) and cerebrospinal fluid (CSF) diagnostics are critical for evaluating central nervous system infections but are often not conducted, resulting in the "Tap Gap." To investigate patient, provider, and health systems factors contributing to the Tap Gap in Zambia, we conducted focus group discussions with adult caregivers of hospitalized inpatients and in-depth interviews with nurses, clinicians, pharmacy workers, and laboratory staff. Transcripts were independently thematically categorized by two investigators using inductive coding. We identified seven patient-related factors: 1) alternative understandings of CSF; 2) alternative information about LPs, including misinformation; 3) mistrust of doctors; 4) consent delays; 5) fear of blame; 6) peer pressure against consent; and 7) association between LP and stigmatized conditions. Four clinician-related factors were identified: 1) limited LP knowledge and expertise, 2) time constraints, 3) delays in LP requests by clinicians, and 4) fear of blame for bad outcomes. Finally, five health systems-related factors were identified: 1) supply shortages, 2) constrained access to neuroimaging, 3) laboratory factors, 4) availability of antimicrobial medications, and 5) cost barriers. Efforts to improve LP uptake must incorporate interventions to increase patient/proxy willingness to consent and improve clinician LP competencies while addressing both upstream and downstream health system factors. Key upstream factors include inconsistently available consumables for performing LPs and lack of neuroimaging. Critical downstream factors include laboratory services that offer poor availability, reliability, and/or timeliness of CSF diagnostics and the reality that medications needed to treat diagnosed infections are often unavailable unless the family has resources to purchase privately.