Key insurance terms that start with "D"

Medical equipment that is prescribed by a doctor and used at home, such as wheelchairs, oxygen tanks, and diabetic supplies. Insurance plans usually cover DME, but you may need to rent or buy it from a plan-approved supplier and may have to pay a copay or coinsurance.

Domestic Partnership

A legal relationship between two unmarried partners. Many health insurance plans now offer domestic partnership benefits, allowing coverage for unmarried couples similar to what spouses receive. You typically need to register your domestic partnership with the plan or state to receive this coverage.

Dependent Coverage

Dependent coverage is the portion of your health insurance plan that extends coverage to your eligible family members — including a spouse, domestic partner, and children up to age 26. Adding dependents to your plan typically increases your monthly premium, but all covered family members share the same plan benefits, network, and cost-sharing structure.

Key things to know about dependent coverage:

Children up to age 26 can remain on a parent’s plan regardless of student status, marital status, or residency
Adding a newborn or adopted child is a qualifying life event that opens a 60-day Special Enrollment Period
Spouse coverage is offered by most plans, but some employer plans charge a spousal surcharge if the spouse has access to their own employer coverage
Domestic partners are recognized by many ACA plans but coverage varies — verify with your specific insurer

On the ACA Marketplace, family plans have a combined family out-of-pocket maximum, but some plans also include an individual embedded limit so no single family member can be held to more than their individual maximum.

Dependent

A dependent is a person who relies on your health insurance coverage — typically a spouse, domestic partner, or child. Dependents can be added to your plan during Open Enrollment or within 60 days of a qualifying life event (like marriage, birth, or adoption).

Under the ACA, you can keep children on your health plan until they turn 26, regardless of whether they are married, in school, living at home, or financially independent. This applies to biological children, stepchildren, and legally adopted children.

Who qualifies as a dependent for health insurance purposes is separate from who qualifies as a dependent for tax purposes. Your insurer’s definition governs who you can add to your plan. Domestic partners are recognized by many plans but are not federally mandated — check your specific plan.

Dental Coverage

Dental coverage is a health benefit that helps pay for preventive and restorative dental care — cleanings, exams, fillings, extractions, crowns, and in some cases orthodontics. It is not automatically included in most adult health insurance plans and typically must be added separately.

On the ACA Marketplace:

Pediatric dental: Covered as one of the 10 Essential Health Benefits on all ACA plans. Children’s dental care is included in your health plan.
Adult dental: Not an Essential Health Benefit. Adult dental coverage is offered as standalone dental plans on the Marketplace or as an optional add-on rider, and is not required to be included in your health plan.

Standalone dental plans are sold separately on the Marketplace and through private insurers. They typically cover:

Preventive care (cleanings, exams, X-rays) at 100% with no deductible
Basic restorative care (fillings) at 70–80% after deductible
Major services (crowns, root canals) at 50% after deductible
Orthodontia (varies widely — lifetime maximum often applies)

If dental care is important to you and your health plan doesn’t include it, adding a standalone dental plan through the Marketplace or a private carrier is usually straightforward and affordable.

Deductible

The amount you pay out of your own pocket for covered health care services before your insurance plan starts sharing costs.

For example, if you have a $1,500 deductible, you pay the first $1,500 of covered care yourself. Once you meet your deductible, your plan begins paying its share. That's where copays come in. A copay is a fixed amount you pay for a covered service (like $30 for a doctor visit), even after your deductible is met.

No matter how much care you need in a year, your spending has a ceiling. That's your out-of-pocket maximum, the most you'll ever pay in a plan year. Once you hit that limit, your insurance covers 100% of covered costs for the rest of the year.

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How your deductible works with your copay and out-of-pocket maximum:

A step-by-step walkthrough showing how the deductible, copay, and out-of-pocket maximum interact during a plan year on an ACA Marketplace Silver plan.
Stage	What Happens	Who Pays	Your Running Total
Before Deductible	You get care before hitting your deductible (e.g., an urgent care visit billed at $400).	You pay the full $400.	$400 toward your $1,500 deductible
Deductible Met	Another $1,100 in covered services. You've now hit your $1,500 deductible.	You pay $1,100. Deductible is now met.	$1,500: deductible met ✓
Copay Kicks In	You see your primary care doctor. The visit is billed at $200, but your copay is $30.	You pay $30. Plan pays the remaining $170.	$1,530 toward your $4,500 out-of-pocket max
Out-of-Pocket Max Reached	A hospital stay. Your share after insurance is $2,970 in coinsurance.	You pay $2,970. Out-of-pocket max is now hit.	$4,500: out-of-pocket max reached ✓
Fully Protected	Any additional covered care for the rest of the plan year.	Your plan pays 100%. You pay $0.	$4,500: you're fully protected for the year

Example uses a hypothetical ACA Silver plan with a $1,500 deductible, $30 primary care copay, and $4,500 out-of-pocket maximum. Actual costs vary by plan. For 2026, the federal out-of-pocket maximum is $10,600 for individuals and $21,200 for families.