The Medicare levy is payable by all Australian resident taxpayers to partly fund Medicare. The amount payable is calculated as 2% of a taxpayer's taxable income.
There are certain reductions/exemptions that are available.The primary exemption is for foreign residents, whereas reductions are applicable for low-income earning individuals/families. These are determined by the ATO based on the information you provide in your tax return.
You are required to pay the Medicare levy surcharge if your income is above the threshold and you do not have the required level of private health cover. The base income threshold is $90,000 for singles and $180,000 for families.
Where you have to pay the Medicare levy surcharge, the ATO will apply the rate that is applicable to your circumstances.