Why your district's required net school spending may be higher than foundation this year

It's not what you think!
I got this question yesterday and I thought it possible, having poked at it today, that others might have come across it and wondered.

It is possible to have a required net school spending level ABOVE foundation this year EVEN IF your district has been spending at or above required spending levels in prior years.

To review: the foundation budget is the state's number of how much the state believe it costs (in total) at a minimum to educate students in your district in a particular year. It includes both your required local contribution and your ch. 70 aid (that makes the difference between what the state says you can afford to pay and the foundation budget).
Net school spending is how much your district must spend on education (which is specifically defined) in a year. This should generally be your foundation budget BUT if your district has spent under foundation in one year, the amount by which the district has underspent gets added to the subsequent year.

There's another reason this may happen, though.
You might remember that when the state made the change from low income to economically disadvantaged, there were some districts that lost out: not all the kids who had been registered for free or reduced lunch appear on state rolls for programs, and most districts saw a corresponding drop in the count of disadvantaged kids. For some districts, it was catastrophic.
There's been work going on around that--I even saw an update on it this week--but in the meantime, the state has passed additional funds as a stopgap for the small number of districts that were hit by this.
But those are not in the foundation budget; they're over and above that.

Let's look at Cambridge, as that's the district I heard the question on. Here's the summary for Cambridge for FY18:

Pretty straightforward: the foundation budget is $84M; Cambridge is a wealthier community, so they pay most of it--the $69.6M--and the state aid is the remaining $14M. Cambridge saw an increase in enrollment over last year, so this is a straight increase in the foundation budget.

But here's what happens in line 8, below that:

Because Cambridge was among the handful of districts that lost out substantially in the switch to economically disadvantaged, the Legislature voted to add a sum to make up for that. For Cambridge, it's just over $100K.

That isn't foundation aid, though, and it didn't change the foundation budget. But the state IS going to require that it be spent on education.

Thus, we end up with a final calculation that looks like this:

If you compare the righthand (FY18) line in blue, which is the Ch. 70 aid, to that line in first chart, you'll see that it's gone up by the additional aid from line 8. Because that is required spending on education, it gets added to the required net school spending, which now is above the foundation budget. So we end up with required spending that is 0.13% over foundation. 

And yes, this happened last year, too. Nobody asked me last year. 

And as always, if I lost you, send me a line!