BACKGROUND Hospital wayfinding is a well-documented source of patient stress, yet people with sensory, cognitive, or mobility-related needs face additional information barriers that generic wayfinding research rarely resolves. Information uncertainty, rather than a simple lack of signage, has recently been proposed as a unifying construct for locating and diagnosing these barriers across the patient journey. OBJECTIVE This study empirically applied a Stage-Touchpoint-Uncertainty coding framework across two structurally contrasting hospitals to identify the elements that constitute information uncertainty during hospital navigation, how these elements are perceived and prioritized by patients with specific needs, and how the resulting uncertainty peaks can inform the prioritization of wayfinding interventions. METHODS We conducted a qualitative, multi-method study combining four rounds of data collection between May 2024 and July 2025 at two university hospitals differing in scale and spatial organization (Hospital A: more than 1,000 beds, decentralized multi-pavilion campus; Hospital B: 890-bed comprehensive center with a historic core). Methods comprised expert accessibility walkthroughs, website accessibility and usability testing with severely visually impaired users, user walkthroughs with mobile eye-tracking and think-aloud protocols, and focus groups homogeneous by impairment type (hearing, developmental or learning, mobility, elderly) evaluating candidate signage designs. In total, 40 participants took part, with a mean age of 38.9 years (range 21-75). RESULTS Observations were coded into a Stage-Touchpoint-Uncertainty matrix across five consolidated journey stages. We coded 451 stage-touchpoint events (Pre-arrival, n=40; Entry, n=59; En-route, n=241; Destination interface, n=84; Exit, n=27). Four cross-stage uncertainty mechanisms emerged: absence, equivocality, perceptual degradation, and cognitive-translation demand. Absence-based uncertainty concentrated in the digital Pre-arrival and physical Entry stages, while equivocality dominated the En-route, Destination, and Exit stages and was the single most frequent mechanism overall. Priorities diverged by impairment group: participants with visual impairment prioritized digital retrievability, the developmental/learning group prioritized redundant multi-channel coding, and the physical/mobility group prioritized functional-eligibility information. CONCLUSIONS Information uncertainty in hospital wayfinding is best characterized along two axes, journey stage and underlying mechanism, which together support stage-specific, mechanism-differentiated intervention design that is generalizable beyond the two hospitals studied, while prioritizing breakdowns corroborated across sources and impairment groups.