Puzzled

Thank you very much WCC. I was researching that questions in lots of places, but not the right place. The response is very much appreciated, especially the link to the applicable final regulation.

This is probably an easy question but I'm lost reading US code trying to answer this. I'll use an extreme example of my question to simplify the basic question. A company has a 401k plan that matches employee contributions 100% up to 4% of salary. Bonuses do NOT qualify for a company match. An employee has an annual salary of $360k, paid equally over 24 pay periods throughout the year, from which the employee contributes 5% from each check toward their 401k. The employee received a $360k bonus on January 5th, before they received their first 'normal' paycheck of the year. Is the employee eligible for a match because the bonus was excluded from the IRS limits? Or are they ineligible for a company match because they reached the IRS annual compensation limit prior to receiving a regular paycheck? Secondly, what code section, etc contains the answer to this question? Thank you for your thoughts!