Voluntary employee contributions (after-tax), associated match and distribution timing

A 401k plan allows for voluntary employee contributions (i.e. after-tax) and the plan matches voluntary employee contributions.

Are there any regulations that would stop an employee from making voluntary employee contributions, receiving the match, then taking a withdrawal of the voluntary employee contributions the next day? Essentially a strategy of obtaining the match then getting their contribution back immediately. 

I understand the document would have to allow it and ACP testing needs to be passed, but is there a regulation that say's this cannot be done?

Thanks

Not explicitly. However the regs do contain a general anti-abuse clause which the IRS could point to in the event of an audit.

Quote

Anti-abuse provisions. Sections 1.401(m)-1 through 1.401(m)-5 are designed to provide simple, practical rules that accommodate legitimate plan changes. At the same time, the rules are intended to be applied by employers in a manner that does not make use of changes in plan testing procedures or other plan provisions to inflate inappropriately the ACP for NHCEs (which is used as a benchmark for testing the ACP for HCEs) or to otherwise manipulate the nondiscrimination testing requirements of this paragraph (b). Further, this paragraph (b) is part of the overall requirement that benefits or contributions not discriminate in favor of HCEs. Therefore, a plan will not be treated as satisfying the requirements of this paragraph (b) if there are repeated changes to plan testing procedures or plan provisions that have the effect of distorting the ACP so as to increase significantly the permitted ACP for HCEs, or otherwise manipulate the nondiscrimination rules of this paragraph, if a principal purpose of the changes was to achieve such a result.

https://www.ecfr.gov/current/title-26/part-1/section-1.401(m)-1#p-1.401(m)-1(b)(3)

While there are special rules for distributions of 401(k) pre-tax contributions, most 401(k) plans are also profit-sharing plans, and profit-sharing plans have additional rules that apply to distributions of amounts that are not pre-tax (elective deferral) contributions.  In general, the definition of a profit-sharing plan in the regulations allows amounts attributable to contributions other than elective deferrals to be distributed after a fixed number of years, the attainment of a stated age, or upon the prior occurrence of some event such as layoff, illness, disability, retirement, death, or severance of employment. Treas. Reg. §1.401-1(b)(1)(ii).  Rulings from the IRS have interpreted this to mean that a plan may allow amounts that are not attributable to elective deferrals to be distributed after they have remained in the plan for at least two years or the employee has participated in the in the plan for at least five years. Rev. Rul. 54-231, Rev. Rul. 68-24, Rev. Rul. 71-295. These rulings are based on the definition of a profit-sharing plan in Treas. Reg. §1.401-1(b)(1)(ii), which generally allows for the funds accumulated under the plan to be distributed after a fixed number of years.