with the NT scan, the rebate is dependent on how the referral is addressed by your doctor. it's an "optional" scan unless there is a medical reason. most GPs will pluck a medical reason to get you the rebate but most won't. for me, my aunt has a disability with similar physical characteristics to DS, and DH's nephew has something similar (don't have a lot of details due to family estrangement). due to that, we got the rebate. i think the IVF factor helped as well (and maybe me being a bigger person - apparently that increases the risks - go figure!)

if it was a healthy person, without family history, BMI or IVF/miscarriage (so basically a sticky beak at bub) then you get no rebate.

as i said, most GP's now will list a clinical reason why it's required which will get you the rebates from medicare