26 CFR § 1.401(a)-30 - Limit on elective deferrals.
(a) General Rule. A trust that is part of a plan under which elective deferrals may be made during a calendar year is not qualified under section 401(a) unless the plan provides that the elective deferrals on behalf of an individual under the plan and all other plans, contracts, or arrangements of the employer maintaining the plan may not exceed the applicable limit for the individual's taxable year beginning in the calendar year. A plan may incorporate the applicable limit by reference. In the case of a plan maintained by more than one employer to which section 413 (b) or (c) applies, section 401(a)(30) and this section are applied as if each employer maintained a separate plan. See § 1.402(g)–1(e) for rules permitting the distribution of excess deferrals to prevent disqualification of a plan or trust for failure to comply in operation with section 401(a)(30).
(b) Definitions. For purposes of this section:
(1) Applicable limit. The term “applicable limit” has the meaning provided in § 1.402(g)–1(d).
(2) Elective deferrals. The term “elective deferrals” has the meaning provided in § 1.402(g)–1(b).
(c) Effective date—(1) In general. Except as otherwise provided in this paragraph (c), this section is effective for plan years beginning after December 31, 1987.
(2) Transition rule. For plan years beginning in l988, a plan may rely on a reasonable interpretation of the law as in effect on December 31, 1987.
(3) Deferrals under collective bargaining agreements. In the case of a plan maintained pursuant to one or more collective bargaining agreements between employee representatives and one or more employers ratified before March 1, 1986, this section does not apply to contributions made pursuant to a collective bargaining agreement for plan years beginning before the earlier of:
(i) The later of January 1, 1988, or the date on which the last collective bargaining agreement terminates (determined without regard to any extension thereof after February 28, 1986), or
(ii) January 1, 1989.