What are the deposit deadlines for ERISA and non-ERISA 403(b) plans?

The deposit timing rules that are applicable to 401(k) plans also apply to elective deferrals under an ERISA 403(b) plan. With regard to non-ERISA 403(b) plans, regulation section 1.403(b)-8(b) requires that deferrals to a 403(b) plan must be transferred to the insurance company within a period that is not longer than is reasonable for the proper administration of the plan. IRS has not defined what is reasonable, but the ERISA rule is likely to be applied here, as we.. These timing rules do not apply to employer contributions made to a 403(b) plan.

§1.403(b)-8 Funding.

(b) Contributions to the plan. Contributions to a section 403(b) plan must be transferred to the insurance company issuing the annuity contract (or the entity holding assets of any custodial or retirement income account that is treated as an annuity contract) within a period that is not longer than is reasonable for the proper administration of the plan. For purposes of this requirement, the plan may provide for section 403(b) elective deferrals for a participant under the plan to be transferred to the annuity contract within a specified period after the date the amounts would otherwise have been paid to the participant. For example, the plan could provide for section 403(b) elective deferrals under the plan to be contributed within 15 business days following the month in which these amounts would otherwise have been paid to the participant.