The plan covers a disbursement of $45.6 million from the Rapid Credit Facility and an immediate debt relief of about $36.5 million under the Catastrophe Containment and Relief Trust.
The credit facility fund will help the authorities fight the epidemic by covering urgent budgetary and balance of payments needs and by strengthening international reserves.
The bank said that the debt relief would help catalyse further assistance from the international community.
Naoyuki Shinohara, Deputy Managing Director of the IMF, said in a statement that the Ebola outbreak continues to cripple the Liberian economy, despite the recent decline in new cases and that the country's fiscal and external financing needs were more pronounced than envisaged.
The Liberian economy is projected to contract in 2015 after stagnation in 2014, thanks to the impact of the epidemic and lower investment in mining and infrastructure.