This is from the Glenbard e-News. It's a pretty good explanation of what maxing the levy is all about and the essentially universal position of all Illinois school administrators and most rubber-stamp Board members.

Note that there isn't a word said about what they actually need. It's all about what they can get.

"2018 tax levy hearing. We have calculated our projected extension consistent with the Property Tax Extension Limitation Law, commonly referred to as the Tax Cap. This law limits the increase in our total property tax extension to 5% or the Consumer Price Index (CPI), whichever is less, not counting new construction or Bond and Interest obligations. We have prepared two calculations.

Most Likely:
We have calculated our most likely extension based on a 2017 calendar year CPI of 2.1% and an estimated new construction amount of $35 million. This calculation represents the total tax extension that we believe the district will most likely receive. We believe our total property tax extension revenue will increase by $3,351,890 or 2.7%. We have estimated an increase in property equalized assessed valuation of 4%.

Manual Override/ Submitted Levy:
School districts will generally levy a dollar amount higher than the expected or "most likely" amount for two primary reasons: 1) If the district's levy request is lower than what the county calculates, the district is only entitled to up to the amount requested; 2) We have not finalized our required levy allocation by fund. Therefore, we intend on requesting higher amounts in each fund to make sure that when we finalize our levy allocation by fund (March/April 2019) we have the opportunity to levy up to the requisite amount.

FUND Most Likely Override
Educational purposes 101,026,635 102,482,330
Operations, Building & Maintenance purposes 17,500,000 18,000,000
Transportation purposes 5,000,000 5,300,000
IMRF purposes 600,000 700,000
Social Security & Medicare purposes 1,800,000 2,000,000

Total: $125,926,635 $128,482,330
Year over Year Increase: 2.7% 4.8%

Our proposed property tax levy submission, excluding the Bond and Interest Levy, is $128,482,330 which represents a 4.8% increase over the prior year's aggregate tax extension ('Override Amount').
DuPage County will calculate our actual property tax extension pursuant to the tax cap, taking into account the CPI and new construction. "