Actuarial value is a measure of how much financial protection you get from a health insurance plan. Two health plans that pay the same percentage of medical expenses are said to have benefits that are actuarially equivalent. For example, two health plans that both pay 85% of the cost of care, with you paying the remaining 15% of costs, are actuarially equivalent.
On your state's Marketplace, you'll be able to compare a few plans with the same actuarial value. Their copays, coinsurance, and deductibles may be similar. But their benefits and premiums may differ. When you're choosing a health plan, look at the costs but also make sure the plans cover the benefits that are most important to you.