Supplemental coverage is misunderstood — either sold aggressively or dismissed outright. The truth is in the middle: it makes sense when your major medical plan leaves a real gap, and doesn't when it duplicates what you already have.
Accident coverage pays a cash benefit for covered injuries. Hospital indemnity pays a daily benefit during hospital stays. Critical illness pays a lump sum on diagnosis of covered conditions.
The right question isn't 'do I need supplemental?' — it's 'what would a real medical event cost me, and where's the gap?'