Background: Progressive supranuclear palsy (PSP) and multiple system atrophy (MSA) are progressive neurodegenerative disorders with complex symptom burden and unpredictable disease trajectories. The ideal timing of palliative care interventions is uncertain given the variable natural history of both diseases. Methods: A systematic review was conducted to identify publications investigating predictors of survival in PSP and MSA. A medical librarian assisted to ensure comprehensive search strategy. Relevant literature on palliative care in PSP and MSA was also reviewed. Results from both searches were qualitatively combined in order to suggest triggers for targeted palliative care throughout the disease trajectory. Results: ‘Milestones’ are well documented and clinically relevant disease points that prompt further care. Important milestones include: frequent falls, cognitive impairment, unintelligible speech, severe dysphagia, wheelchair dependence, urinary catheterisation, and nursing home placement. PSP-Richardson syndrome accumulates milestones earlier than PSP-Parkinsonism or MSA. Many PSP patients already have falls and cognitive impairment at the time of diagnosis. Time from milestone to death is variable. Conclusions: Milestones can be used to trace disease progression and help predict survival. Clinical milestones are likely to be important triggers for targeted palliative care interventions including the early incorporation of a palliative approach to care or referral to specialised palliative care services.