Patients with life-threatening hematologic cancer experience insomnia and fatigue, distress, and pain symptoms that worsen insomnia during and following hospitalization for high-dose chemotherapy. Despite an urgent need, there are limited symptom management protocols that comprehensively target the challenging treatment (i.e., inpatient, outpatient) and symptom demands faced by hematologic cancer patients. We developed and tested a 6-session, therapist-led, telehealth intervention for hematologic cancer patients following discharge from inpatient treatment (Nite2Day). Nite2Day teaches mindfulness meditations and behavioral strategies to improve insomnia and related fatigue, distress, and pain symptoms. Nite2Day demonstrated strong feasibility, acceptability, and significant improvements to primary (insomnia; d=1.20) and secondary outcomes (fatigue, distress, mindfulness; ds=.38-.89). Nite2Day does not address the inpatient setting where patients describe sleep quality as especially poor. This pilot randomized controlled trial will extend Nite2Day to the inpatient setting (Nite2Day+) and assess its feasibility, acceptability, engagement, and outcome patterns. Hematologic cancer patients (N=60) reporting insomnia symptoms during hospitalization will be randomized (1:1) to Nite2Day+ or Usual Care. Nite2Day+ will be delivered via a self-paced mobile app in the hospital and include: 1) mindfulness meditations promoting acceptance of the challenging inpatient setting; 2) brief videos on sleep education (e.g., sleep drive, circadian rhythm) and behavioral strategies to improve inpatient sleep quality (e.g., stimulus control, daytime activity); and 3) tools to manage inpatient sleep disruptions (e.g., sleep mask, ear plugs). Once discharged home, patients will transition to the previously tested, 6-session protocol. We hypothesize that: 1) Nite2Day+ will be feasible (accrual N=60/24 months; <25% attrition; >75% adherence to assessments and intervention), acceptable (M>3/5 satisfaction with procedures; M>3/4 satisfaction with Nite2Day+), and engaging (Nite2Day+ app log-in, video/skills practice >2x/week); and 2) Nite2Day+ will improve insomnia symptom severity (primary outcome) and secondary outcomes (fatigue, distress, pain, pre-sleep arousal, mindfulness, symptom management self-efficacy) from baseline to hospital discharge and after the 6-session protocol, compared to Usual Care. Dr. Fisher will receive advanced training and expert mentorship in behavioral sleep and cancer symptom management and behavioral intervention development for inpatient and outpatient settings, and randomized trial designs and statistical methods for optimizing behavioral treatment regimens to improve the transition from inpatient to outpatient settings. This training will help Dr. Fisher pursue a future sequential multiple assignment randomized trial assessing insomnia and symptom management strategies that are responsive to challenging treatment (i.e., inpatient, outpatient) ...