Marketplace and many small-group plans fall into Bronze, Silver, Gold, and Platinum tiers based on how costs are split. Bronze carries the lowest premiums and highest cost-sharing, Platinum the reverse. Tiers reflect actuarial value, not quality of care.
Actuarial value (AV) is the share of total covered costs a plan pays on average across a standard population. The ACA metal tiers are defined by AV: Bronze ~60%, Silver ~70%, Gold ~80%, Platinum ~90%; the member pays the rest.
A catastrophic plan has very low premiums and a very high deductible, and it’s limited to people under 30 or those with a hardship/affordability exemption. It mainly protects against worst-case medical costs.
In the ACA-regulated individual and small-group markets, plans are grouped into metal tiers by “actuarial value”, the average share of covered costs the plan pays: Bronze ~60%, Silver ~70%, Gold ~80%, Platinum ~90%. A lower tier means lower premiums but higher cost-sharing when you use care.