The mistakes show up every vest: employees treat sell-to-cover as the full tax bill, then get a surprise at filing. Cost basis on the 1099 is often wrong, which looks like double taxation. RSUs pile into company stock without a sell plan. Mega backdoor Roth only works if the 401(k) allows after-tax contributions and in-plan conversions, and many people never check. ESPP “free money” can crowd out Roth space when cash flow is tight.

A founding-member digital system: mega backdoor Roth “does my plan allow it” checklist, ESPP hold-versus-sell notes, RSU vest tax versus withholding, equity concentration worksheet, and calculator-style sheets. Educational only. Not tax, legal, or investment advice. Confirm rules with your plan administrator and a qualified advisor.