Info for highly compensated employees (generally the upper end of the upper management tier) is in Section J part 2. It is currently broken out by base compensation, bonus, "other" compensation (probably things like different taxable allowances, also severance), retirement/other deferred compensation and non-taxable benefits (probably stuff like health and life insurance. I believe the amounts in the respective columns reflect only EMPLOYER PAID amounts -- so for example in the retirement column the amount the employee themselves directed to a retirement plan would not be included there, since that money was paid out in salary and then put into the retirement bucket by the employee. But employer contribution to retirement plans would fall in this column.
Be cautious about using this as the source for "normative" info, as orgs only need to report these details for highly compensated employees who may be subject to caps on their benefits depending on how many employees overall are contributing to retirement, etc. You cannot guess percentage match, etc. by looking at these numbers. Orgs may also have a tiered approach to benefits -- for example, at my old non-profit, regular employees started off with a 5% retirement match that went up to 7.5% and eventually 10% based on years of service. But again, highly compensated employees would not have gotten those amounts because of IRS caps.
Highly recommend people look at this part of the PF990 for an organization they are employed by, applying to, or considering donating to.
