Population aging is expected to increase healthcare expenditures in OECD countries more than government revenues, putting pressure on government fiscal positions. Taxes on labor income are more vulnerable to aging than other tax types like consumption taxes. Deteriorating subnational fiscal positions may be difficult to overcome if subnational governments have limited revenue raising autonomy. Reforms to fiscal federalism may be needed to address imbalances across levels of government as the impact of aging is asymmetric depending on their expenditure and revenue responsibilities.