For three years, your 401(k) has been operating under rules its own plan document may never have mentioned. The higher RMD age, hardship self-certification, the new part-time eligibility rules — plans have been running them in good faith while the paperwork waited. That grace period ends this year.
The deadline
Under IRS Notice 2024-2, calendar-year qualified retirement plans must be formally amended for the SECURE Act, the CARES Act, and SECURE 2.0 by December 31, 2026. The amendments apply retroactively to each provision's original effective date, which is why plans could operate first and document later.
Not every plan shares that date. Collectively bargained plans have until December 31, 2028, and governmental plans until December 31, 2029. Tax-exempt sponsors of 457(b) plans had an earlier deadline of December 31, 2025, which has already passed.
The mandatory amendments include raising the required minimum distribution age to 73 (and to 75 in 2033), eliminating lifetime RMDs from designated Roth accounts inside plans, the Roth catch-up mandate for high earners, distributions for victims of domestic abuse, expanded eligibility for long-term part-time employees, and hardship withdrawal self-certification.
The IRA reprieve
In January 2026, the IRS issued Notice 2026-9 extending the SECURE 2.0 amendment deadline to December 31, 2027 for IRAs under Sections 408(a) and (h), individual retirement annuities under 408(b), SEP arrangements under 408(k), and SIMPLE IRA plans under 408(p). The stated reason: the IRS is still developing model language for trustees, custodians, and issuers to use.
A separate extension arrived in May. Notice 2026-33 pushed the amendment deadline to December 31, 2027 for the optional qualified long-term care distribution provision, for defined contribution plans that aren't governmental or collectively bargained.
Neither extension moves the general December 31, 2026 date for qualified 401(k) plans. That distinction is the practical point: if you hold both a workplace 401(k) and a SEP or SIMPLE IRA, the two are on different clocks.
Why a document deadline matters to you
This is the employer's legal obligation, not yours — but the consequences are shared. A qualified plan that misses its amendment deadline risks disqualification, and disqualification is not purely an employer problem. It can affect the tax treatment of participant balances.
There is also a second clock running. Plans using pre-approved documents are in a restatement cycle that runs from July 2026 through July 2028, a separate requirement from the SECURE amendments.
Practical takeaways
- Watch for a Summary of Material Modifications. When your plan is amended, you should receive updated disclosure. Read it — it is the clearest statement of which optional features your employer actually adopted.
- Ask HR about discretionary provisions. Mandatory items get amended automatically. Optional ones your plan has been offering informally — emergency savings accounts, the student loan match, long-term care distributions — require a deliberate decision to formalize. Q4 is when that decision gets made.
- Self-employed savers should not treat 2027 as idle time. If you sponsor a SEP or SIMPLE IRA, confirm your custodian's timeline rather than assuming the extension is handled.
- Verify the Roth catch-up mechanics. The statutory threshold is $145,000 in prior-year FICA wages, indexed to $150,000 for 2026. If you are near it, confirm your plan can accept Roth catch-up contributions before year-end.
- Don't change behavior because of this. A retroactive amendment documents what already happened. It should not alter contributions you have already made.
For 2026, the 401(k) elective deferral limit is $24,500, with an $8,000 catch-up at 50 and older and an $11,250 super catch-up for ages 60–63. The IRA limit is $7,500 plus a $1,100 catch-up. Those numbers govern what you do between now and December. The amendment deadline governs whether the plan document says so.
Sources: IRS Notice 2024-2; IRS Notice 2026-9; IRS Notice 2026-33; Journal of Accountancy; Husch Blackwell; Sidley Austin