Error Prompt: CMN.ATO.IITR.000605
Suggested Solution: Go to Label M2 of the "Medicare" section, under "Private health insurance policy details", and select the appropriate "Tax Code".

Click the dropdown arrow under the "Tax code" column and then select the applicable code. See below image:
Below is the image when the tax code is already selected:

Related guides:
- CMN.ATO.IITR.000600
- Entering Number of Dependant Children for Medicare Levy Surcharge Threshold in LodgeiT
- Private Health Codes