A reduction in force is lawful. What creates liability is a selection process that cannot be explained, or that turns out to fall disproportionately on a protected group.
Define the business rationale first, in a document: the units affected, the cost target, the operational reason. A rationale reverse-engineered after selections is worth little.
Set criteria before names. Skills required going forward, performance history where it is documented and comparable, and objective factors such as certification. Avoid criteria that are proxies — flexibility, energy, fit, and long-term potential all invite an age claim.
Apply consistently within a defined decision unit, and document the scoring. Inconsistent application across managers is the most common vulnerability.
Run the adverse impact analysis before the decisions are final, under privilege, comparing selection rates by age, sex, race and other protected characteristics. If a disparity appears, the time to revisit criteria is now.
Notice and release. Where a release of age claims is sought from a group, statutory requirements apply: extended consideration periods, revocation rights, advice to consult counsel, and disclosure of the job titles and ages of those selected and not selected in the decision unit. Defects void the age release while leaving the employer bound.
Mass layoff notice statutes may require advance notice; the thresholds count in ways that surprise employers.