How Marriage Affects Taxes for High-Income Parents in California and Washington

By Kevin Luu, Co-Founder and Chief Learning Officer. Reviewed on 2026-09-30.

Taxes are usually lower after marriage when one spouse earns most of the income, and they can be higher when both spouses are high earners. For 2026, the joint brackets are exactly double the single brackets up to the 35% rate, so most couples see no change or a “marriage bonus.” Above that point, and for several thresholds that are not doubled for couples, two high-earning spouses can pay more together than they would as two single filers.

For a dual-income household earning $750,000 to $3 million in California or Washington, the penalty is real but usually manageable. In the worked example below it is about $11,000 to $16,000 for 2026, and it varies with how income is split between spouses and whether you itemize. The bigger risk is withholding: two W-2 jobs plus RSU vests often leave a large balance due in April. Below is how each piece works, with 2026 numbers.

Where the 2026 federal brackets stop doubling for couples

For 2026, the married filing jointly (MFJ) bracket edges are twice the single edges through the 32% bracket, which ends at $512,450 for couples and $256,225 for single filers (IRS Rev. Proc. 2025-32). The break comes at the top:

• Single filers pay 35% up to $640,600 of taxable income, then 37%.
• Married couples filing jointly pay 35% up to $768,700, then 37%. Twice the single edge would be $1,281,200.

So for 2026, every dollar of joint taxable income between $768,700 and $1,281,200 is taxed at 37% instead of the 35% it would face if the same income were split across two single returns. That 2-point gap is the core federal marriage penalty for high earners. The standard deduction is exactly doubled ($32,200 MFJ versus $16,100 single for 2026), so it creates no penalty.

Thresholds that are not doubled for married couples

Several federal rules use a married threshold that is less than twice the single one. At this income level, four matter:

Sources: IRS Additional Medicare Tax Q&A, IRS Net Investment Income Tax, P.L. 119-21 (SALT cap), IRS Child Tax Credit.

On the Child Tax Credit: for 2026 it is $2,200 per qualifying child, reduced by $50 for each $1,000 of MAGI over $400,000 on a joint return. A married couple with two children loses the full $4,400 at $488,000 of MAGI. Most families reading this get no Child Tax Credit, married or not, which also answers a common question about “2 dependents on taxes”: at this income, children change the bill mainly through dependent care benefits, not the credit.

Worked example: two physicians in California earning $600,000 each

Assumptions (illustrative): each spouse earns $600,000 in W-2 wages, household income $1.2 million, two children under 12, California residents, 2026 federal figures, standard deduction used to isolate the bracket effect.

How the numbers come together:

• Federal brackets. On the joint return, $399,100 of income sits above $768,700 and is taxed at 37%. Split across two single returns, all of it would stay in the 35% bracket. 2% of $399,100 is $7,982.
• Additional Medicare Tax. As single filers, 0.9% applies to $400,000 of wages each. Jointly, it applies to $950,000 ($1.2 million minus $250,000). Each employer still withholds 0.9% only on wages it pays above $200,000, so the $1,350 gap shows up as a balance due at filing.
• California. California’s 2025 joint brackets are double the single brackets, so ordinary rates create no penalty. The 1% Behavioral Health Services Tax is different: it applies to taxable income over $1,000,000 with the same threshold for joint filers (FTB Form 540 booklet). Assuming California taxable income of about $1,190,000 after deductions, roughly $190,000 is exposed. Two single filers at about $600,000 each would owe none.

If they itemize: the SALT cap adds more

Many California couples with a mortgage itemize. For 2026, the SALT cap starts at $40,400 and is reduced by 30% of MAGI above $505,000, never below $10,000. As single filers with $600,000 of MAGI, each spouse’s cap would be $11,900 ($40,400 minus 30% of $95,000), or $23,800 combined. Jointly, with $1.2 million of MAGI, the couple gets $10,000. The extra $13,800 of lost deduction, worth 35% to 37% at these incomes, adds roughly $5,000, bringing the total penalty in this example to about $16,000 for 2026. California itself does not follow the federal SALT change (FTB).

Worked example: one earner at $900,000 sees a marriage bonus

Assumptions (illustrative): one spouse earns $900,000 in salary and RSUs at a Bay Area or Seattle tech company, the other spouse stays home with the children, 2026 federal figures, standard deduction.

• Filing single: taxable income $883,900, federal income tax about $283,000.
• Filing jointly: taxable income $867,800, federal income tax about $243,250.
• Difference: about $39,750 less federal income tax for 2026, plus $450 less Additional Medicare Tax (the threshold rises from $200,000 to $250,000).

The joint return lets the earner’s income fill the wider married brackets. This is the classic marriage bonus, and it is why one-earner couples nearly always pay less after marriage. An unmarried parent with a qualifying child could file as head of household, which has wider brackets than single, so the real bonus versus that status is smaller. Our guide to whether a stay-at-home parent files taxes covers the non-earning spouse’s side, including the spousal IRA.

Washington couples: federal penalty only, for now

Washington has no individual income tax on wages for 2026 (WA DOR), so for a Seattle-area couple the marriage penalty is the federal part above: bracket compression, Additional Medicare Tax and the SALT cap. Two state points still apply:

• Capital gains tax. Washington’s capital gains tax (7%, rising to 9.9% on taxable gains above $1,000,000) has one standard deduction ($278,000 for 2025, the latest published) whether you are an individual or a married couple (WA DOR). Two unmarried partners who are not registered domestic partners each get their own deduction. A married couple or registered domestic partnership gets one. This matters when selling a block of long-held company stock.
• The new income tax from 2028. Washington enacted a 9.9% tax on AGI over $1,000,000 for individuals and joint filers, effective January 1, 2028 (WA DOR FAQ). As written, the threshold is the same for a single person and a married couple, which would create a state marriage penalty for two high earners. Details are pending DOR guidance.

Should high earners file separately to avoid the penalty?

Usually not. Married filing separately rarely reduces the total bill, and it closes doors. The dependent care FSA limit drops to $3,750 per spouse for 2026 instead of $7,500 per household, and other benefits narrow or disappear. In California and Washington there is an extra catch: both are community property states, so wages earned during the marriage are generally split 50/50 between the two separate returns (IRS Pub. 555). That split largely recreates the joint result. Separate returns can still make sense for liability reasons, such as a spouse’s unresolved tax debt. For what happens if a married person files as single, see filing as single when married.

Your marital status on December 31 sets your filing status for the whole year (IRS Pub. 501). So a late-December wedding makes a couple married for the whole tax year, while an early-January wedding leaves them single for the year before. The difference is one year of the bonus or penalty shown above.

The W-4 decision two working spouses need to make

The most common surprise is not the penalty itself. It is a five-figure bill in April because neither employer withholds as if the other income exists. Three causes stack up:

1. Two jobs on default W-4s. Each payroll applies the full joint brackets to one salary, so each spouse is underwithheld. The 2026 Form W-4 fixes this in Step 2: use the IRS Tax Withholding Estimator, or check the Step 2(c) box on both spouses’ forms.
2. RSU and bonus withholding at 22%. Supplemental wages are often withheld at the flat 22% federal rate (37% only above $1,000,000 for the year), while this household’s top bracket is 35% or 37% (IRS Pub. 15). Each vest adds to the gap.
3. Additional Medicare Tax. As in the example above, each employer withholds based on its own wages, not the couple’s combined total.

Can both parents claim the children on the W-4? Credits for dependents go on one spouse’s W-4 only, in Step 3. At this income the Child Tax Credit is fully phased out, so Step 3 should normally be left blank on both forms. A practical method: run the estimator after the first RSU vest of the year, then add a fixed extra amount per paycheck in Step 4(c) on the higher earner’s W-4. Our step-by-step W-4 guide walks through each line.

Benefits, gifts and accounts that change with marriage

• Daycare costs. Daycare is not a deduction, but a dependent care FSA lets you pay up to $7,500 per household of childcare for 2026 with pre-tax wages, if your employer has adopted the higher limit. At this income it is typically more valuable than the child and dependent care credit, and the same expenses cannot be counted twice. For a married couple, the tax-free amount is generally limited to the lower-earning spouse’s earned income, so a family with a stay-at-home parent typically cannot use it (IRS Pub. 503).
• Gift splitting for the children. A married couple can give $38,000 per child for 2026 (two times the $19,000 annual exclusion) by electing gift splitting on Form 709, or front-load up to $190,000 per child into a 529 with the five-year election and gift splitting.
• Non-citizen spouse. Many tech and biotech families include a spouse who is not a US citizen. Gifts to that spouse above $194,000 for 2026 can use up lifetime exemption, which affects how you title the house and brokerage accounts.
• Retirement. At joint MAGI above $252,000, neither spouse can contribute directly to a Roth IRA for 2026, so both typically use the backdoor route. Ask our team about workplace plans and benefits, including the mega backdoor Roth.

What to write down for your kids

Record three things in one page: which filing status you chose and why, what you set on each W-4 (and the date you last checked it), and how you think about the trade between two careers and the extra tax that comes with them. Your children will someday face the same question with their own partners. “Conversations fade. Documentation compounds.”

Common questions

Are taxes less when married for two high earners?

Usually not. For 2026, once joint taxable income passes $768,700, two high earners pay 37% on income that would stay at 35% on two single returns. Add the non-doubled Additional Medicare Tax threshold, a single SALT cap per return and California’s 1% tax above $1,000,000, and the extra cost in our $1.2 million example is about $11,000 to $16,000 for 2026. The amount varies widely with how income is split and whether you itemize.

What is the best way to fill out a W-4 if married and both work?

Use the IRS Tax Withholding Estimator once both spouses’ pay stubs are in hand, then enter the result in Step 4(c) on one W-4. If you skip the estimator, check the Step 2(c) box on both forms. Recheck after large RSU vests or a bonus, because supplemental withholding at 22% is usually well below this household’s top rate.

Next step

Pull both spouses’ latest pay stubs and last year’s return, and run the IRS Tax Withholding Estimator before the next RSU vest. If you want a second set of eyes on filing status, withholding and the rest of the household’s tax picture, our tax management team covers it in the Tax & Wealth Assessment. For ways to bring MAGI down in the first place, see how to reduce MAGI.

This is general education, and the right move depends on your family’s full picture.

Written by

Kevin Luu

Co-Founder and Chief Learning Officer, Bright Advisers

Kevin has advised high-income W-2 tech and biotech families since 2015, and leads the education-first Age Five Family Office from Brea, California.

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