A health plan with a higher deductible and lower premium that qualifies you for an HSA.
An HDHP trades a higher deductible for a lower monthly premium and is the only kind of plan that lets you contribute to a Health Savings Account. It can be cost-effective for relatively healthy people who can cover the deductible, especially when paired with HSA tax advantages. Heavy medical users may prefer a lower-deductible plan.
Choosing an HDHP unlocks the ability to fund a triple-tax-advantaged HSA.