In This Article
- How Does a SEP-IRA Work for NJ Small Business Owners?
- How Does a Solo 401(k) Work and When Is It Better Than a SEP-IRA?
- How Does a SIMPLE IRA Work for Businesses With Employees?
- What Are the NJ State Tax Benefits of Retirement Plan Contributions?
- Key Takeaway
- Ready to File With Confidence?
Contributing to a retirement plan is one of the most effective tax reduction strategies available to NJ small business owners - and the NJ treatment depends on which plan type you use. A SEP-IRA allows contributions up to 25% of net SE income (max $70,000 for 2025, $72,000 for 2026 per IRS Notice 2025-67). A Solo 401(k) offers higher combined limits. Important NJ nuance per N.J.S.A. 54A:6-21: Solo 401(k) employee deferrals AND employer (match/profit-sharing) contributions ARE excludable from NJ gross income; defined benefit employer contributions are also excludable. But SEP-IRA and SIMPLE IRA contributions are NOT deductible for NJ purposes - they instead create NJ basis recoverable tax-free in retirement under the 3-Year Rule or General Rule. (This corrects earlier guidance that swept all SE retirement plans into the no-deduction bucket - V5 audit / N.J.S.A. 54A:6-21 May 2026.)
Contributing to a retirement plan is one of the most effective tax reduction strategies available to NJ small business owners; NJ treatment varies by plan type per N.J.S.A. 54A:6-21.
How Does a SEP-IRA Work for NJ Small Business Owners?
Contributions up to 25% of net self-employment income, max $70,000 for 2025 ($72,000 for 2026 per IRS Notice 2025-67). Easy to set up, no annual filing. Deadline extends to tax return due date. Main drawback: must contribute same percentage for employees. NJ treatment: SEP-IRA contributions are NOT deductible against NJ gross income; they create NJ basis recoverable tax-free in retirement.
How Does a Solo 401(k) Work and When Is It Better Than a SEP-IRA?
Both employee deferrals ($23,500 for 2025, $24,500 for 2026 per IRS Notice 2025-67) and employer contributions (up to 25%). Combined max $70,000 for 2025 ($72,000 for 2026), plus $7,500 catch-up if 50+ ($8,000 for 2026) or $11,250 for ages 60-63 under SECURE 2.0. Employee deferral deadline is December 31. NJ treatment: Solo 401(k) employee deferrals AND employer match/profit-sharing contributions ARE excludable from NJ gross income per N.J.S.A. 54A:6-21 - meaning Solo 401(k) gives both federal AND contemporaneous NJ tax savings, unlike SEP/SIMPLE IRAs.
How Does a SIMPLE IRA Work for Businesses With Employees?
For businesses with up to 100 employees. Employee contributions up to $16,500 for 2025; $17,000 for 2026 per IRS Notice 2025-67. Catch-up $4,000 (age 50+) for $21,000 total; super catch-up $5,250 (ages 60-63) for $22,250 total. Employer match up to 3% or 2% non-elective. Setup deadline is October 1. NJ treatment: SIMPLE IRA contributions are NOT deductible against NJ gross income; they create NJ basis.
How Does a Defined Benefit Plan Work?
Defined benefit (DB) pension plans target a specified annual benefit at retirement and require actuarial calculations annually. For 2026, the §415(b) annual benefit limit is $290,000 (per IRS Notice 2025-67, up from $280,000 in 2025). DB plans can produce very high deductible contributions for older high-income sole proprietors, but require ERISA compliance, annual actuarial work, and continuing contribution obligations. NJ treatment: Employer contributions to a DB plan ARE excludable from NJ gross income per N.J.S.A. 54A:6-21.
What Are the NJ State Tax Benefits of Retirement Plan Contributions?
NJ treatment depends on the plan type per N.J.S.A. 54A:6-21. Solo 401(k) and Defined Benefit plans: Employer + employee contributions ARE excludable from NJ gross income, producing contemporaneous NJ tax savings. SEP-IRA and SIMPLE IRA: NOT deductible for NJ purposes - contributions create NJ basis recoverable tax-free in retirement under the 3-Year Rule (full recovery in first 36 months of distributions) or General Rule (proportional). For maximum NJ tax efficiency, prefer Solo 401(k) over SEP-IRA when feasible.
Key Takeaway
Retirement plan contributions produce a dollar-for-dollar reduction in FEDERAL taxable income in the contribution year. For NJ, the outcome depends on the plan: Solo 401(k) and Defined Benefit contributions reduce NJ gross income contemporaneously per N.J.S.A. 54A:6-21; SEP-IRA and SIMPLE IRA contributions do NOT - they instead create NJ basis recoverable tax-free in retirement. At a 32% federal + 6.37% NJ rate, a $10,000 Solo 401(k) employer contribution saves $3,837 in combined federal+NJ taxes today. The same $10,000 in a SEP-IRA saves $3,200 federally today and leaves $637 of NJ tax savings to recover later via basis. Choose the right plan for your business structure, employee situation, and contribution goals.
Related reading: Year-End Tax Moves for NJ Business Owners | S-Corp Salary vs. Distributions | Top 5 Overlooked Deductions | Tax planning services
## Frequently Asked Questions
What is the maximum SEP-IRA contribution for self-employed?
Self-employed individuals can contribute up to 25% of net self-employment income to a SEP-IRA, with a maximum of $70,000 for 2025. The actual calculation uses adjusted net self-employment income (after the self-employment tax deduction), so the effective rate is approximately 20% of net Schedule C income. Contributions are due by the tax return filing deadline, including extensions.
What is the advantage of a Solo 401(k) over a SEP-IRA?
A Solo 401(k) allows both employee deferrals ($23,500 for 2025) and employer contributions (up to 25% of compensation), potentially enabling higher total contributions. It also permits catch-up contributions of $7,500 for those age 50 and older. Unlike a SEP-IRA, the employee deferral portion must be elected by December 31 of the tax year.
Do retirement plan contributions reduce NJ state taxes?
It depends on the plan type. Solo 401(k) and Defined Benefit plans: Per N.J.S.A. 54A:6-21, employee deferrals (Box 12 Code D for 401(k)) and employer match/profit-sharing/DB contributions ARE excludable from NJ gross income, giving both federal AND contemporaneous NJ tax savings. SEP-IRA and SIMPLE IRA: NJ does NOT allow a current-year deduction; contributions create NJ basis recoverable tax-free in retirement under the 3-Year Rule (full recovery in first 36 months of distributions) or General Rule (proportional). For NJ-resident business owners, Solo 401(k) is usually more tax-efficient than SEP-IRA. (May 2026 V5 audit correction: earlier guidance swept all SE plans into the no-deduction bucket - that was incorrect under N.J.S.A. 54A:6-21.)
Can I set up a retirement plan after year-end?
It depends on the plan type. A SEP-IRA can be established and funded up to the tax return due date, including extensions. A Solo 401(k) must be established by December 31 of the tax year, though employer contributions can be made until the filing deadline. A SIMPLE IRA must be established by October 1 of the year for which contributions are being made.
Ready to File With Confidence?
Tax rules change frequently. If anything in this guide applies to your situation, a quick review with a CPA can prevent costly mistakes. Greg Monaco is a NJ-licensed CPA (License #20CC04711400) who prepares every return personally.
