My school's take on IEPs is this:
Class teachers have to differentiate the curriculum every day ie deliver it in different ways to different groups. The level of differentiation is dictated by the spread of abilities ie how bright are the brightest kids, how many of them are there and how low is the lowest common denominator. This will be different for each class of kids so there is no 'absolute' level.
My dd1's school believe that dd1's needs can be met with the usual differentiation ie lump her in with the lowest-attainers. Simple as. On this basis my dd1 does not have and will never have an IEP.
I actually disagree with this because it does not address the reasons behind the difficulty in each subject ie the level of work is simpler but they are forever changing subject in maths and not giving my dd1 a chance to do the over-consolidating she needs to do. In short what they do does not actually address my dd1's needs (which is primarily slow processing, poor working memory and ultimately lack of confidence). My dd1 does not have a low IQ but weakness in particular areas, needs extra, multi-sensory methods, excellent teaching, time for processing and repetition, repetition, repetition. Making the work easier is therefore only half the problem, SpLD is by definition NOT the same as having a low IQ. Therefore lumping her in with the less bright kids is not necessarily the way to meet the needs of SpLD kids.
Having said that I do appreciate that teachers are totally up against it trying to meet the differing needs of different children. There is only so much they can do. As the school is unable to meet my dd1's needs properly we employ a specialist tutor and this is where most of my dd1's maths learning happens.
IMO supermum's ds should absolutely be getting suppport from school and therefore should definitely be on School Action (my dd1 is) even if there is no IEP.
Having said all this supermum's ds school may have different criteria for using an IEP. It might be worth finding out.
Handy xxxxx