Taxes are one of the most complex—and often daunting—parts of financial planning, particularly for high earners. The stakes are high: even small missteps can have lasting financial consequences, making proactive tax planning essential.
If you’re earning a six-figure income, you’re facing a significant tax burden. The U.S. federal tax system is progressive—your marginal tax rate climbs as your income rises, reaching as high as 37%. Add state and local taxes, and your effective tax rate can easily exceed 50%.
The Numbers That Matter
- $15,569 Average federal tax bill for households earning $100k-$200k
- $48,343 Average federal tax bill for households earning $200k-$500k
This is where tax planning becomes critical. Making intentional financial decisions with taxes in mind—rather than discovering tax consequences after the fact—can save you thousands annually. Even modest savings compound quickly: reducing your tax bill by just $1,000 per year translates to over $7,000 in additional wealth after five years (at 6% returns).
Below, we’ve outlined 10 mistakes high earners frequently make. If any resonate with your situation, now is the time to address them.
Mistake No. 1: Not Maxing Out Tax-Advantaged Accounts
How It Works
The government incentivizes saving for retirement, education, and healthcare by offering tax breaks. Yet many high earners fail to take full advantage.
What You Can Do
401(k)/403(b): Contribute up to $23,500 annually ($31,000 if age 50+) to reduce taxable income dollar-for-dollar. Plus, employer matches are free money.
Health Savings Accounts (HSA): Triple tax benefit—contributions, growth, and withdrawals (for medical expenses) are all tax-free. Limit: $4,300 (individual) or $8,550 (family).
529 College Savings Plans: State tax deductions on contributions; growth and withdrawals for education are tax-free.
CPA Insight
For high earners, the gap between what you could shelter and what you actually do can represent your single largest tax planning opportunity. We recommend reviewing these accounts as part of annual tax planning.
Mistake No. 2: Selling Investments Without Timing Them Right
How It Works
Capital gains taxes vary dramatically based on how long you’ve held an asset. A single day can cost you thousands.
- Short-term gains (held ≤1 year): Taxed as ordinary income at rates up to 37%
- Long-term gains (held >1 year): Taxed at preferential rates of 0%, 15%, or 20%
For high earners, there’s an additional 3.8% Net Investment Income Tax on gains above $200,000 (single) or $250,000 (married).
What You Can Do
Before selling any significant investment, check how long you’ve held it. Waiting a few weeks could save you 17-37% in taxes on gains.
CPA Insight
Before selling any significant investment, check how long you’ve held it. Waiting a few weeks could save you 17-37% in taxes on gains. We maintain a calendar view of all client holdings to optimize this timing.
Mistake No. 3: Ignoring Tax-Loss Harvesting
How It Works
Use underperforming investments strategically. Sell them at a loss to offset capital gains from winners, reducing your tax bill.
What You Can Do
- Timing is critical: Harvesting must be completed by December 31st to benefit the current tax year.
- Watch the wash-sale rule: You can’t buy back the same investment within 30 days or the loss is disallowed.
- Use the right accounts: Focus on taxable brokerage accounts, not tax-deferred accounts like 401(k)s.
CPA Insight
Tax-loss harvesting is especially valuable in down market years. Our team reviews all client portfolios in Q4 to identify harvesting opportunities before year-end.
Mistake No. 4: Overlooking Roth Conversion Strategies
How It Works
High earners face income limits on direct Roth IRA contributions ($165,000 for singles / $246,000 for married). But there’s a workaround.
What You Can Do
Backdoor Roth: Contribute to a traditional IRA, then immediately convert to a Roth. Withdrawals after age 59½ are tax-free.
Mega Backdoor Roth: If your 401(k) allows after-tax contributions, you can funnel much larger amounts into a Roth (limited only by the total annual contribution cap of $69,500).
CPA Insight
Roth conversions require precise execution—missed deadlines or incorrect procedures can disqualify the entire conversion. This is a strategy worth getting professional guidance on.
Mistake No. 5: Not Accounting for the Alternative Minimum Tax (AMT)
How It Works
High earners may face this parallel tax system. You calculate taxes two ways and pay the higher amount.
What You Can Do
AMT thresholds (2025): $88,100 (single) / $137,000 (married filing jointly)
AMT rates: 26% or 28%—lower than marginal rates, but can eliminate certain deductions.
CPA Insight
If you’re subject to AMT, certain tax-planning strategies (like maximizing 401(k) contributions or harvesting losses) lose their effectiveness. We calculate AMT exposure early in the year to inform the entire tax strategy.
Mistake No. 6: Undervaluing Health Savings Accounts
How It Works
HSAs are the gold standard of tax-advantaged accounts—and most high earners aren’t using them to their full potential.
- Contributions are tax-free
- Growth is tax-free
- Withdrawals for medical expenses are tax-free
- You can let it grow: Receipts don’t need to match withdrawals in the same year—save receipts and withdraw tax-free anytime in the future.
What You Can Do
If you’re on a high-deductible health plan, maxing your HSA should be a priority. It’s essentially a retirement account with even better tax treatment than an IRA.
CPA Insight
If you’re on a high-deductible health plan, maxing your HSA should be a priority. It’s essentially a retirement account with even better tax treatment than an IRA.
Mistake No. 7: Assuming You’re Not “Wealthy Enough” for Estate Tax
How It Works
The federal estate tax exemption is $13.99 million (2025)—high enough that most people ignore it. But don’t overlook state taxes.
What You Can Do
- State estate taxes: Several states impose their own estate taxes with thresholds as low as $1-3 million
- Inheritance taxes: A few states impose taxes on beneficiaries receiving inherited assets
CPA Insight
Even if federal estate tax isn’t a concern, state-level exposure can be significant. We recommend a coordinated approach with your attorney to optimize both income and estate taxes.
Mistake No. 8: Having Only a Will (Not a Complete Estate Plan)
How It Works
A will is just one piece of the puzzle. It doesn’t control jointly owned property, accounts with named beneficiaries, or incapacity situations.
What You Can Do
- Wills go through probate: Public, time-consuming, and expensive
- Trusts avoid probate: Faster, private, and more flexible. They can include detailed instructions for beneficiaries and control when/how assets are distributed.
- You also need: Powers of attorney (financial and healthcare) and advance directives for incapacity scenarios
CPA Insight
Estate planning is a collaborative process. We work alongside your estate planning attorney to ensure tax efficiency and coherence across all documents.
Mistake No. 9: Attempting to “Escape” U.S. Taxes by Moving Abroad
How It Works
U.S. citizens are subject to federal income tax on worldwide income, regardless of where they live. Moving abroad doesn’t eliminate your tax obligation.
What You Can Do
- You must file annually, or face penalties up to 25% of unpaid taxes plus interest
- Foreign tax credit available: You can offset U.S. taxes with income taxes paid to other countries, preventing double taxation
CPA Insight
If you’re a U.S. citizen or resident alien, we strongly recommend consulting with a CPA experienced in international tax before relocating. The rules are complex and mistakes are costly.
Mistake No. 10: Missing Out on Charitable Giving Strategies
How It Works
Charitable donations can be tax-deductible, but most donors leave tax savings on the table by not structuring gifts strategically.
What You Can Do
Donor-Advised Funds (DAF): Contribute assets now, claim the deduction now, and distribute to charities over time. Example: contribute $100k to a DAF for a $100k deduction, then give $2k/month to charity over 50 months.
Qualified Charitable Distributions (QCD): If you’re 70½+, transfer up to $100k directly from an IRA to charity—this counts toward required minimum distributions and avoids increasing your taxable income.
Donate appreciated assets (not cash): You deduct the full fair-market value of appreciated stock or real estate while avoiding capital gains tax on the appreciation.
CPA Insight
Charitable planning is one of the most underutilized tax strategies. If you donate $25k+ annually, structured giving could save you thousands. Let’s discuss your philanthropic goals—we can design a plan that maximizes both your impact and your tax benefits.
The Bottom Line
High earners face a uniquely complex tax landscape. Federal rates, state taxes, net investment income tax, AMT, and capital gains considerations all intersect—and missing even one of these items can cost you thousands.
The good news? Most of these mistakes are preventable with deliberate planning. That $5,000-10,000 invested in professional tax guidance typically returns multiples of that investment through deferred or eliminated taxes, optimized retirement savings, and strategic asset positioning.
Your next step: Review your situation against these 10 traps. If any sound familiar—or if you’re unsure whether you’re optimized—now is the time to act. Tax planning is most effective when done proactively, not reactively. Every high earner’s situation is unique. We’d love to review yours and identify opportunities specific to your circumstances. Feel free to reach out for a free consultation.
