
Additional Medicare Tax 0.9%: How Form 8959 Reconciles Employer Withholding With Filing Status Thresholds
A 0.9% surtax applies to earned income above $200,000 (single) or $250,000 (joint), but employers withhold using a flat $200,000 per-job trigger. Form 8959 reconciles the two rules — generating a balance due for most dual-income couples and a credit for over-withheld single earners.










