You Maxed Your 401k and HSA. Here Is What Is Actually Left for W-2 Earners at $300K+ (2026)

You make $300,000 or more on a W-2. The 401k is full. The HSA is full. Your CPA files the return and tells you that you are already doing the right things. And the question that never gets answered is the only one you asked: what is left?

Here is the honest version. Six moves need nothing but your own paperwork. A few larger ones need a rental, a real business, or a spouse with time. And a handful of things being pitched to high earners right now are either investments wearing a tax costume or transactions the IRS has already named.

Why pure W-2 income has so few levers

A paycheck is the hardest kind of income to shelter. The employer reports the wage. The withholding already happened. You cannot deduct unreimbursed employee expenses on a federal return. There is no entity to route anything through.

That leaves three real categories:

1. Things that come out of the paycheck before it is taxed.
2. Things that change what your money does after it is taxed.
3. Business or rental activity that creates losses you are allowed to use.

Everything below fits in one of those three.

Where $300,000 actually lands in 2026

For a single filer, the 32% bracket starts at $201,775 of taxable income and the 35% bracket starts at $256,225. Take $300,000 in salary, subtract the $24,500 401k deferral and the $16,100 standard deduction, and you are around $259,400. Your top dollars sit in the 35% bracket. Add 1.45% Medicare plus the 0.9% additional Medicare tax above $200,000 of wages, then add your state.

Married filing jointly is a different story. The 32% bracket does not start until $403,550. A joint filer at $300,000 is still in the 24% bracket. Run your own numbers with the marginal vs effective tax rate calculator before you plan around a rate you assumed.

Two other numbers matter at this income. The 3.8% net investment income tax starts at $200,000 of modified AGI for single filers and $250,000 for joint filers, and those thresholds have never been indexed. The state and local tax deduction cap is $40,400 in 2026, and it phases down by 30 cents for every dollar of MAGI above $505,000.

The ranked list

Ordered by how much a $300K W-2 earner can realistically move, with what each one costs you in effort and risk.

Group 1: no business, no rental, no spouse needed

Mega backdoor Roth

The mega backdoor Roth is the biggest move most $300K W-2 earners have never used. In 2026 your elective deferral is $24,500, but the total that can land in your 401k from all sources is $72,000. The gap is after-tax contribution room, and once it is converted to Roth it grows and comes out tax-free.

The math is simple. $72,000 minus your $24,500 deferral minus your employer match equals your room. With no match, that is $47,500.

It is not a deduction. You pay full tax on the money going in. What you buy is thirty years of growth that is never taxed again, which is worth more than most one-year deductions at this income.

Two questions decide it, and your plan administrator can answer both in one call: does the plan allow after-tax contributions, and does it allow in-plan Roth conversions or in-service withdrawals. If either answer is no, the strategy is closed to you this year.

Backdoor Roth IRA

The 2026 IRA limit is $7,500, with a $1,100 catch-up at 50 and over. Roth IRA contributions phase out between $153,000 and $168,000 for single filers and $242,000 and $252,000 for joint filers, so you are well past the direct route.

The backdoor Roth IRA is a non-deductible traditional IRA contribution converted to Roth. The trap is the pro-rata rule: if you hold any pre-tax IRA money, including a SEP or a rollover IRA, part of the conversion is taxable. Rolling that balance into your current 401k first usually clears it.

Dependent care FSA

The dependent care FSA got materially better. For decades the limit was $5,000. Starting in 2026 it is $7,500. That is $7,500 of pay that never shows up as wages. At a 35% federal rate plus state and Medicare, it is worth roughly $3,000. Your employer has to amend the plan to adopt the new limit, so check before you assume it is there.

Deferred compensation

If your employer offers a nonqualified deferred compensation plan, you can push a slice of salary into a future year. It works when you expect a lower rate later, such as a planned sabbatical, a move to a no-income-tax state, or retirement.

Be clear about the risk. Deferred comp is an unsecured promise from your employer. If the company fails, you are a general creditor. The election is also locked well before the money is earned, and you cannot change your mind mid-year.

Tax-loss harvesting

Tax-loss harvesting means selling a position that is down, booking the loss, and buying something similar but not substantially identical. Losses offset gains dollar for dollar, and $3,000 of net loss can go against ordinary income each year. The rest carries forward with no expiration. Stay out of the 30-day window on either side of the sale or the wash sale rule disallows it.

Charitable bunching and donor-advised funds

Two rules changed for 2026. Only the part of your charitable giving above 0.5% of AGI is deductible, so at $300,000 of AGI the first $1,500 does nothing. And the tax value of itemized deductions is now capped at 35% for filers in the top bracket.

Bunching still works. You put two or three years of giving into a donor-advised fund in one year, itemize that year, and take the standard deduction ($16,100 single, $32,200 joint) in the others. Giving appreciated stock instead of cash still avoids the capital gain. The benefit is just smaller than it was.

Municipal bonds

Muni interest is free of federal income tax and is not net investment income, so it dodges the 3.8% NIIT as well. In-state bonds usually skip state tax too. This is not a deduction, it is a place to hold bonds. Compare the tax-equivalent yield before you move anything.

Equity compensation and the 83(b) election

If part of your pay is stock, the timing decisions here can be worth more than every other item on this list. Selling RSUs the day they vest avoids a concentrated bet. Holding shares more than a year moves gains to the long-term rate. And if you receive restricted stock, an 83(b) election lets you pay tax on the low value at grant instead of the higher value at vest.

That election has a hard 30-day deadline from the transfer. There is no extension and no late filing. The IRS now has a standard form for it, Form 15620.

Group 2: needs a rental

The short-term rental route

This is the one strategy that lets a full-time W-2 employee use rental losses against wages, and it is the one most often oversold.

Rentals are automatically passive under Section 469, which normally blocks the loss. The regulations carve out property where the average period of customer use is seven days or less. Clearing that test removes the automatic label. It does not finish the job. You still have to materially participate, and most owners rely on the test that requires more than 100 hours of your time with no other person, including a cleaner or a co-host, spending more.

Pair that with a cost segregation study and 100% bonus depreciation, which the 2025 law made permanent for qualifying property acquired after January 19, 2025, and a first-year deduction in the tens of thousands is possible.

Now the parts that do not make the sales page. The hours are real and you need a contemporaneous log. The depreciation is recaptured when you sell. And a property that only works because of the deduction is a bad property. Read the full short-term rental loophole guide and cost segregation guide before you commit capital.

Long-term rentals and REPS

Real estate professional status needs more than 750 hours and more than half of your working time in real property trades or businesses. If you have a full-time job, you cannot clear the second half of that test. This route is closed to you personally.

Group 3: needs a spouse or a side business

A spouse with real estate professional status

This is the honest workaround. If your spouse is not working full time elsewhere, they can meet the 750-hour and majority-of-time tests, and on a joint return their status opens up losses against your wages. It is also one of the most examined positions in the code, so the time log has to exist as the year happens, not after a notice arrives.

A real side business

Self-employment income creates access to a solo 401k, which adds employer contributions on top of what your day job already uses, inside the same $72,000 ceiling. Above a certain profit level an S-corp election can cut self-employment tax. And the Section 199A deduction is now permanent, with 2026 threshold amounts of $201,750 for single filers and $403,500 for joint filers.

All of this requires income that actually exists. A business started only to create deductions is a hobby with paperwork.

What is being sold to you

These are the pitches high earners hear most. Each one is a real thing. None of them is what the pitch says.

The short-term rental loophole. Real, and covered above. What gets skipped in the pitch: the seven-day average is measured across the year, material participation is a separate test, the hours are yours and not your manager's, and recapture arrives at sale.

Oil and gas working interests. Real. Section 469(c)(3) excludes a working interest in oil or gas from the passive rules, so intangible drilling costs can offset wages, and IDCs often run 60% to 80% of well cost. The catch is structural: the exception only applies if you hold the interest in a form that does not limit your liability, which usually means a general partnership interest with the personal exposure that comes with it. And the well can be dry. This is an investment with a tax feature, not a tax plan.

Captive insurance. Real for large operating businesses with real risk to insure. For everyone else, the IRS finalized regulations on January 14, 2025 that put certain micro-captive arrangements back on the listed transaction list, with others named transactions of interest. Both carry disclosure on Form 8886, and advisors file Form 8918. A structure you have to disclose as a listed transaction is not a quiet deduction.

Conservation easements. Syndicated versions are effectively dead. A 2022 law disallows the deduction when a partnership claims more than 2.5 times the partners' relevant basis, with a strict 40% penalty, and final regulations issued October 8, 2024 name these as listed transactions. If someone is showing you a 4-to-1 or 5-to-1 write-off ratio, you are looking at the exact fact pattern that got named.

Solar. The residential clean energy credit under Section 25D ended for expenditures after December 31, 2025. If you are being sold residential solar in 2026 on the strength of a 30% federal credit, that credit is gone. Commercial solar rules are separate and are their own analysis.

Tax-free retirement with an indexed universal life policy. There is no deduction. Premiums are after-tax. The "tax-free income" is a policy loan, and if the policy lapses with a loan outstanding, the gain becomes taxable at the worst possible moment. Fees and rising cost of insurance eat returns quietly. If you want tax-free retirement money and you have 401k after-tax room sitting unused, use the room first.

The order I would work in

1. Call your plan administrator about after-tax contributions and in-plan Roth conversions.
2. Fill the mega backdoor Roth room if it exists.
3. Do the backdoor Roth IRA, after clearing any pre-tax IRA balance.
4. Turn on the dependent care FSA at the new $7,500 limit if it applies.
5. Check your withholding against your real bracket with the payroll withholding estimator.
6. Harvest losses in the brokerage account before year-end, not in December panic.
7. Decide on charitable bunching with the 2026 floor in the math.
8. Only then look at a rental, and only if the deal stands up without the tax result.

Most people at $300,000 skip steps 1 through 7 and jump to step 8 because that is the step with a salesperson attached.

Sources

• IRS, 401(k) limit increases to $24,500 for 2026, IRA limit increases to $7,500
• IRS, Tax inflation adjustments for tax year 2026
• IRS, Revenue Procedure 2025-19 for 2026 HSA limits
• IRS, Net Investment Income Tax
• Federal Register, Micro-Captive Listed Transactions and Micro-Captive Transactions of Interest
• Federal Register, Syndicated Conservation Easement Transactions as Listed Transactions
• Congressional Research Service, Expiration and Carryforward Rules for the Residential Clean Energy Credit

Educational content only. It is not individual tax, legal, or investment advice. Confirm every number against your own facts with a qualified professional before you act.