Every Jan, DALPA puts out a "Check your Checks" to help get ready for tax time. One of things they cover is the 401K money. Here is the copy/paste from earlier this year.

"As mentioned above, Company contributions to the Delta 401(k) Retirement Plan for Pilots would have stopped if the combined contributions (yours and the Company’s) reached $58,000 in 2021, per IRC 415(c)(1)(A). Further Company payments (16%) continued in the form of taxable wages and are listed under Earnings as “401(k) Excess.”Note: Catchup contributions (max $6,500) are not counted against your individual contribution limit ($19,500) or the combined contribution limit ($58,000).

If you reached the income limit set forth by IRC 401(a)(17) of $290,000 in 2021, the Company contributions to the Delta 401(k) Retirement Plan for Pilots ceased, regardless of whether you’ve reached the 415(c)(1)(A) ($58,000) limit. Upon reaching the 401(a)(17) income limit, all further Company contributions are received as taxable wages and listed under Earnings as “401(k) Excess Plus.”

For tracking purposes, the contributions that apply to the combined limit are listed under Employer Contributions using the term “Company 401(k) Fixed.”