26 CFR § 1.403(b)-9 - Special rules for church plans.
(a) Retirement income accounts -
(1) Treatment as a section 403(b) contract. Under section 403(b)(9), a retirement income account for employees of a church-related organization (as defined in § 1.403(b)-2) is treated as an annuity contract for purposes of §§ 1.403(b)-1 through 1.403(b)-8, this section, § 1.403(b)-10 and § 1.403(b)-11.
(2) Retirement income account defined -
(A) There is separate accounting for the retirement income account's interest in the underlying assets (namely, there must be sufficient separate accounting in order for it to be possible at all times to determine the retirement income account's interest in the underlying assets and to distinguish that interest from any interest that is not part of the retirement income account);
(C) The assets held in the account cannot be used for, or diverted to, purposes other than for the exclusive benefit of plan participants or their beneficiaries (and for this purpose, assets are treated as diverted to the employer if there is a loan or other extension of credit from assets in the account to the employer).
(ii) Plan required. A retirement income account must be maintained pursuant to a program which is a plan (as defined in § 1.403(b)-3(b)(3)) and the plan document must state (or otherwise evidence in a similarly clear manner) the intent to constitute a retirement income account.
(3) Ownership or use constitutes distribution. Any asset of a retirement income account that is owned or used by a participant or beneficiary is treated as having been distributed to that participant or beneficiary. See §§ 1.403(b)-6 and 1.403(b)-7 for rules relating to distributions.
(4) Coordination of retirement income account with custodial account rules. A retirement income account that is treated as an annuity contract is not a custodial account (as defined in § 1.403(b)-8(d)(2)), even if it is invested solely in stock of a regulated investment company.
(i) The amount of the distribution form has an actuarial present value, at the annuity starting date, equal to the participant's or beneficiary's accumulated benefit, based on reasonable actuarial assumptions, including regarding interest and mortality; and
(6) Combining retirement income account assets with other assets. For purposes of § 1.403(b)-8(f) relating to combining assets, retirement income account assets held in trust (including a custodial account that is treated as a trust under section 401(f)) are subject to the same rules regarding combining of assets as custodial account assets. In addition, retirement income account assets are permitted to be commingled in a common fund with amounts devoted exclusively to church purposes (such as a fund from which unfunded pension payments are made to former employees of the church). However, unless otherwise permitted by the Commissioner, no assets of the plan sponsor, other than retirement income account assets, may be combined with custodial account assets or any other assets permitted to be combined under § 1.403(b)-8(f). This paragraph (a)(6) is subject to any additional rules issued by the Commissioner in revenue rulings, notices, or other guidance published in the Internal Revenue Bulletin (see § 601.601(d)(2)(ii)(b) of this chapter).
(7) Trust treated as tax exempt. A trust (including a custodial account that is treated as a trust under section 401(f)) that includes no assets other than assets of a retirement income account is treated as an organization that is exempt from taxation under section 501(a).
(c) Special deduction rule for self-employed ministers. See section 404(a)(10) for a special rule regarding the deductibility of a contribution made by a self-employed minister.