Fitness for work and the aging workforce: medical assessment as a de facto mechanism of retirement in the United Kingdom after the abolition of the default retirement age.

Background: Fitness for work is the judgement that a person is medically able to perform a role safely. This review considers the concept to have been shaped for a younger workforce expected to leave employment at a fixed retirement age. As populations have aged and mandatory retirement ages have been abolished, it is the instrument that remains available for questions it was not designed to answer. Methods: This review traces the origins of the concept and examines what fitness for work means when applied to an aging workforce and the risks of relying on it at scale. Results: Aging is gradual and individual and is poorly suited to a categorical fitness judgement applied to a gradual process. Universal screening of older workers is impractical, and using age itself as the trigger may amount to direct age discrimination, lawful only where the employer can show that it is a proportionate means of achieving a legitimate aim. An unfit finding made without accommodation functions as an exit from work, and the limitation is not confined to older workers, since the duty to make reasonable adjustments attaches to disability alone. When the United Kingdom abolished its default retirement age in 2011, the law left capability, defined in statute by reference to health, as a route for ending an older worker's employment. Fitness-for-work assessment may therefore function as a de facto retirement mechanism, operating where mandatory retirement once did but without its transparency or legal constraints. Where a formal unfitness procedure exists, as in France, the sequence from assessment to exit is recorded and falls more heavily on workers over 50. The United Kingdom has no equivalent procedure and no equivalent data, so the risk is structural and unmeasured. Conclusion: Fitness for work could operate as a quiet successor to the mandatory retirement that was abolished as discriminatory, not through deliberate misuse but through the unguarded working of the mechanism. Abolishing mandatory retirement was the right course. What is missing is an obligation to find accommodation, modify work, or redeploy, attached to the assessment rather than to the person assessed.