Chicago Bulls
Their apron payroll (contracts, dead money, drafted rookies, and unlikely incentives) is $182.7M, against a first apron of $209.0M and a second apron of $221.7M. Their apron payroll counts $2.3M in unlikely bonuses, incentive money a player probably won't earn that counts against the aprons but not the cap or tax.
Staying under the aprons preserves the full toolkit: the full mid-level, the bi-annual exception, and sign-and-trade flexibility. Several of those tools hard-cap a team at an apron once used, which is why the margins matter.
The rule behind this
The first apron is a spending line a few million above the luxury tax. Crossing it costs a team roster-building tools rather than just money: no acquiring players via sign-and-trade, no full mid-level exception (only the smaller taxpayer MLE), no bi-annual exception, no signing buyout players who earned more than the MLE, and trades must return salary within 110% of what goes out.
More Bulls questions
Numbers come straight from the live Bulls cap sheet, recomputed whenever the data updates.