The holder of a private pilot licence may act as:
You may not exercise any pilot privileges unless you are in possession of a valid medical certificate. A category 3 medical is required to act as a private pilot. It is valid for a period of 60 months when under 40 years of age and for a period of 24 months for those 40 years of age or older.
For example, if a 35 year old private pilot successfully completes a category 3 medical examination on March 13, 2015, the medical will remain valid until April 1, 2020 (always round up to the first of the next month). If a 45 year old private pilot successfully completes a category 3 medical examination on March 13, 2015, the medical will remain valid until April 1, 2017.