Background: Serious illness communication training often focuses on sharing medical information, discussing goals of care, and supporting patients and caregivers. Few communication frameworks explicitly integrate psychosocial concepts to improve therapeutic efficacy. Objectives: To develop, implement, and evaluate a half-day workshop that integrates psychotherapeutic concepts into palliative care communication across four professional settings. Methods: Using Kern's six-step curriculum development model, we created an interactive workshop focused on psychological formulation and countertransference. The workshop was delivered to four cohorts: a national conference, an international palliative care congress, a fellows' education day, and a social work-focused summit. Pre-, post-, and eight-week follow-up surveys were administered, assessing Kirkpatrick's four levels of training evaluation. Results: In total, 203 palliative care clinicians completed the presurvey, 168 completed the post-survey, and 79 completed the eight-week follow-up. Knowledge of formulation increased from a median of 3 (interquartile range [IQR] 2-4) preworkshop to 5 (IQR 4-5) at eight weeks (p < 0.001). Knowledge of countertransference increased from 4 (IQR 3-4) to 5 (IQR 4-5) (also p < 0.001). Satisfaction was high (92% satisfied or highly satisfied), and most participants reported meaningful impact on their clinical practice (89%), teaching (93%), and team collaboration (93%) at eight-week follow-up. Conclusions: A multisite, half-day workshop significantly enhanced palliative care clinicians' knowledge and perceived application of core psychotherapeutic concepts. Future work should explore remote and longitudinal modalities to support ongoing skill integration.