Background: We sought to evaluate the effect of an integrated prospective payment program (IPP) on knowledge of hospice care and willingness to participate in hospice care among family members of patients on prolonged mechanical ventilation (PMV).; Methods: Between November 2013 and April 2014, we used paper-based survey questionnaires from 64 institutions to evaluate knowledge, willingness, and related factors among the main caregivers of patients on PMV regarding hospice care and to determine whether their decisions for the patients were affected by the IPP.; Results: The average ages of the respondents and patients on PMV were 51.9 y and 70.8 y respectively; 70.6% of the respondents knew about the Hospice Palliative Care Act (HPCA), and 42.3% of the medical staff had introduced hospice care-related information to patients and caregivers in Taiwan. Among the caregiver respondents, 67.6% agreed to write a letter of intent regarding the choice of hospice care or limited life-sustaining treatment. In total, 66.2% (16.1 + 50.1%) of the respondents agreed to hospice care for their family members (ie, the patients on PMV) when the condition was terminal. The factors of greater HPCA knowledge among the patients on PMV were IPP participation, female sex, and coma status. Factors leading to higher levels of HPCA knowledge included age ≥ 65 y being married, higher income, awareness of the law, and being introduced to hospice care by medical staff.; Conclusions: High levels of hospice care knowledge were unrelated to willingness to participate. HPCA knowledge was greater in the IPP group than in the non-IPP group; however, there was no significant difference in the willingness to agree to hospice care. It is recommended that individuals be encouraged to express their medical decisions.