In Payroll spheres it's call "Gross Up" where the payments is increased to cover the receivers expected tax liability (Federal and State). So at the end of the day the individual ends up with an amount equal to (or close) to the desired amount post tax.
Let's say for example someone takes our a HELOC for $130,000 to pay a porn star for an NDA to protect a clients political campaign. The candidate will them reimburse the individual after the election. If the candidate pays the individual $130,000, the individual will lose money.
Using the $130,000 reimbursement as an example, if the individual pays 32% Income Taxes then for spending $130,000 the individual receives back $130,000 that is then claimed as income resulting in $41,600 in taxes leaving $88,400 in his pocket.
I don't think there as been any claim that Cohen didn't claim the money paid by the Trump Organization on his taxes.
His tax fraud conviction was for taxi medallions, not the money FPOTUS#45 paid back for boinking a porn star.
WW