LodgeiT will  calculate Medicare Levy Surcharge (prefill+other info), make sure that you have activated "Medicare" via financial image. 

It is important to use the correct tax code for your private health otherwise the tax calculations made by LodgeiT may be different than what you would expect.

Find the summary via "Estimate" tab-


1. How LodgeiT Calculates Medicare Levy Surcharge (MLS)?

-> It depends on Person’s taxable income, superannuation contributions, number of dependent children, Number of days not liable for surcharge and also from spouse’s taxable income and superannuation contributions. ATO link

2. Medicare levy also depends on spouse’s income.

3. Reason of threshold increase can be an individual has dependent child (IT8)

4. Please check with the ATO calculator what should be the amount of Medical Levy Surcharge your client should get. ATO Calculator 

5. Reason of "exceed threshold",  not only taxable income is the basis of computation of Medicare Levy Surcharge, here are other surcharge that can be a reason, learn more

6. Incorrect calculation

-> Check details ie date of birth for the person and spouse

Visit this link to know more more about ATO codings -