For high-income taxpayers, business owners, investors, and families with Korea-U.S. ties, year-end is the time to review income, withholding, retirement contributions, and foreign accounts while there is still time to act.
Review Withholding and Estimated Payments
RSU vesting, stock sales, bonuses, K-1 income, or business profits can leave a balance due if too little tax was paid. If income rose sharply in 2026, consider an extra estimated payment or a withholding increase.
You generally avoid an underpayment penalty by paying at least 100% of last year’s tax, or 110% if last year’s AGI exceeded $150,000. Because withholding is treated as paid evenly through the year, a December withholding increase can work better than a late estimated payment.
Check Retirement Contributions
Several limits increased for 2026: the 401(k) deferral limit is $24,500, and the age-50+ catch-up is $8,000. Under SECURE 2.0, employees who earned more than $150,000 in FICA wages from their employer in 2025 must make any catch-up contributions as Roth. If the plan has no Roth option, they may lose the catch-up entirely. Business owners should also confirm employer contribution deadlines.
Reconcile Investment and Equity Compensation
Check that RSU and option income on your W-2 matches your brokerage records, since Form 1099-B often shows RSU basis as zero. If you exercised ISOs, holding the shares past December 31 may trigger AMT, while selling in the same year avoids AMT but creates ordinary income.
Review Foreign Accounts
If you have Korean bank, investment, or pension accounts, confirm your FBAR (FinCEN Form 114) and Form 8938 obligations. Missing these filings can trigger penalties even when no tax is due.
Organize Business and Rental Records
Separate business and personal expenses, reconcile accounts, and prepare a year-end P&L. Rental owners should organize records of repairs, improvements, interest, taxes, and management fees, plus participation logs if rental losses are part of a tax strategy.
SKJ CPA helps individuals, families, and business owners review U.S. and Korea-related tax issues before filing season begins.