New empirical analysis shows that fiscal policy in Timor-Leste has been unable to stabilize macroeconomic fluctuations over the last couple of decades. Timor-Leste collects relatively little non-oil tax revenue and the large public expenditure envelope relies heavily on withdrawals from the Petroleum Fund. Characterized by low tax collection and low tax effort, Timor-Leste's tax system simultaneously displays long-run buoyancy of greater than one-suggestive that growth has improved fiscal sustainability over time. This study concludes that tax policy reforms are important to support domestic resource mobilization efforts. The introduction of a modern value-added tax (VAT) can complement other tax administration reforms. Finally, greater mobilization of domestic resources should go together with more efficient public spending.