An impediment which may reduce or block quality of care and/or increase cost, and which may hinder the achievement of the goal(s). "A barrier impacts specific interventions or other plan activities and may necessitate their modification. Barriers are situations outside the health care system which nonetheless reduce or block quality of care and also increase cost. Barrier may also impact on goals achievement if modifications to interventions cannot effectively overcome identified barriers." - HL7 Care Plan Domain Analysis Model.