Retirement Account Tax Rules

All tax-advantaged retirement accounts fall into one of two tax structures: Traditional (pre-tax) or Roth (after-tax). The difference is simply when you pay the tax — now, or in retirement.

Feature	Traditional (Pre-Tax)	Roth (After-Tax)
Tax on contributions	Deductible (reduces taxable income now)	No deduction (contributed with after-tax dollars)
Growth	Tax-deferred	Tax-free
Withdrawals in retirement	Taxed as ordinary income	Tax-free (if qualified)
Required minimum distributions	Yes, starting at age 73	No (Roth IRA only; Roth 401k has RMDs unless rolled to Roth IRA)
Best if you expect...	Lower tax rate in retirement than today	Higher tax rate in retirement (or tax rates rise)

The decision between Traditional and Roth is essentially a bet on your future tax rate. Young, low-income earners usually benefit more from Roth. High-income earners in peak earning years often prefer Traditional. Many financial advisors recommend contributing to both to hedge against future tax rate uncertainty.

Tip: Roth accounts are particularly valuable for young investors because decades of tax-free compounding can far outweigh the upfront tax cost of the contribution.

The IRS adjusts contribution limits annually for inflation. For 2025, the limits are as follows:

Account Type	2025 Limit (Under 50)	2025 Limit (Age 50+)	Catch-Up Type
Traditional or Roth IRA	$7,000	$8,000	+$1,000 standard catch-up
401(k), 403(b), 457(b)	$23,500	$31,000	+$7,500 standard catch-up
401(k) — ages 60–63 (SECURE 2.0)	$23,500	$34,750	+$11,250 super catch-up
SIMPLE IRA	$16,500	$20,000	+$3,500 catch-up
SEP-IRA	Lesser of 25% of compensation or $69,000	Same	No catch-up
Solo 401(k) — total	$70,000	$77,500	Includes employee + employer contributions

• Roth IRA income limits (2025): Phase-out begins at $150,000 MAGI (single) and $236,000 (married filing jointly). Above $165,000 / $246,000, direct Roth IRA contributions are not allowed — but the backdoor Roth remains available.
• IRA deadline: IRA contributions for 2025 can be made up to Tax Day 2026 (April 15, 2026). 401(k) contributions must be made by December 31, 2025.

Tip: If you have a 401(k) with a match, contribute at least enough to get the full employer match before contributing to an IRA. The match is an immediate 50–100% return on your contribution.

Required minimum distributions (RMDs) are mandatory annual withdrawals from tax-deferred retirement accounts. The IRS requires them so it can eventually collect the deferred tax. The SECURE 2.0 Act (enacted 2022) raised the RMD starting age from 72 to 73 (and eventually 75 starting in 2033).

Account Type	RMD Required?	Starting Age	Notes
Traditional IRA	Yes	73	RMD by Dec 31 each year (April 1 in first year)
Traditional 401(k)	Yes	73	Can delay if still working for the plan sponsor
Roth IRA	No	—	No RMDs during owner's lifetime
Roth 401(k)	No (post-2024)	—	SECURE 2.0 eliminated Roth 401(k) RMDs starting in 2024
Inherited IRA (non-spouse)	Yes	Varies	10-year rule applies; annual RMDs required years 1–9

The RMD amount is calculated by dividing the prior year-end account balance by the IRS Uniform Lifetime Table life expectancy factor for your age. For example, at age 73 the factor is 26.5, so a $1,000,000 balance produces a $37,736 required distribution.

Warning: Failing to take a required minimum distribution triggers a penalty of 25% of the amount not withdrawn (reduced to 10% if corrected in a timely manner under SECURE 2.0). This is one of the largest penalty rates in the tax code.

Withdrawing from a tax-advantaged retirement account before age 59½ generally triggers a 10% early withdrawal penalty on top of any income tax owed. However, the IRS provides a list of exceptions.

Exception	Applies To	Notes
Substantially equal periodic payments (SEPP / Rule 72(t))	IRA & 401(k)	Must take equal payments for at least 5 years or until 59½, whichever is later
Disability	All accounts	Total and permanent disability required
Death (beneficiary withdrawals)	All accounts	No penalty; income tax still applies on Traditional accounts
First-time home purchase	IRA only	Up to $10,000 lifetime; Roth principal always penalty-free
Higher education expenses	IRA only	Penalty waived; income tax still applies on Traditional
Health insurance premiums (unemployed)	IRA only	Must have received unemployment compensation for 12 consecutive weeks
Age 55 separation from service	401(k) only	Must have separated from the employer in or after the year you turn 55
Emergency personal expense (SECURE 2.0)	All accounts	Up to $1,000/year; repayable within 3 years

For Roth IRAs, contributions (not earnings) can always be withdrawn at any time without tax or penalty — only the earnings portion is subject to the 10% penalty and income tax if withdrawn early before the account is 5 years old.

Tip: The Roth IRA's penalty-free access to contributions (not earnings) makes it an excellent dual-purpose account — retirement savings that can also serve as an emergency backstop if absolutely necessary.

High earners who exceed the Roth IRA income limits ($165,000 single / $246,000 MFJ in 2025) can still access Roth benefits through two workarounds.

• Backdoor Roth IRA: Contribute to a Traditional IRA (non-deductible), then immediately convert it to a Roth IRA. Because the contribution was after-tax, no income tax is owed on the conversion — only on any earnings that accrued between contribution and conversion.
• Mega backdoor Roth: Some 401(k) plans allow after-tax (non-Roth) contributions above the standard $23,500 limit — up to the total plan limit of $70,000. These after-tax contributions can then be converted to Roth inside the 401(k) or rolled out to a Roth IRA.

Strategy	Annual Roth Capacity Added	Requires
Backdoor Roth IRA	$7,000 ($8,000 if 50+)	No pre-tax IRA balances (avoids pro-rata rule)
Mega backdoor Roth	Up to $46,500 additional (in 2025)	401(k) plan that allows after-tax contributions and in-plan Roth conversion

The pro-rata rule: If you have existing pre-tax IRA balances (Traditional IRA with deductible contributions), the backdoor Roth conversion is taxed proportionally across all IRA money — you cannot isolate the non-deductible contribution. Rolling pre-tax IRA funds into a 401(k) before doing the backdoor conversion eliminates this issue.

Warning: The backdoor Roth IRA must be reported on Form 8606. Failing to file this form can result in double taxation on the same dollars. Work with a CPA the first time you execute this strategy.