Here's the case for a 12-month emergency fund instead of the standard 6-month recommendation, and who it applies to.

The standard 6-month advice assumes: salaried employment in a liquid job market, predictable monthly expenses, and no major upcoming non-emergency expenses.

For people who should consider 12 months: single-income households with dependents where a job loss would be catastrophic, self-employed or contract workers with volatile income, workers in specialized industries or geographic areas with long job search timelines, anyone over 55 in a field where re-employment typically takes longer.

The opportunity cost of 12 months vs 6 months in a HYSA earning 4%: approximately $800/year on $20,000. That's the insurance premium for the extra cushion. For the scenarios above, that premium is worth paying.

For stable dual-income households with no dependents in competitive job markets: 3-4 months is probably sufficient and the excess above that could be better deployed in investments.