Health Insurance Glossary (2026 Edition)
Every definition uses this year's real numbers — the 2026 contribution percentages, poverty guidelines, and limits — so you can act on what you read, not just understand it.
MAGI (Modified Adjusted Gross Income)
The income number that determines your ACA subsidy: AGI plus tax-exempt interest, non-taxed Social Security, and excluded foreign income.
The ACA subsidy: a refundable tax credit that caps your benchmark plan cost at 2.1%–9.96% of income in 2026, for incomes between 100% and 400% of FPL.
Advance Premium Tax Credit (APTC)
The premium tax credit paid monthly to your insurer in advance, based on your estimated income — reconciled on your tax return.
The second-lowest-cost silver plan in your area — the reference price all ACA subsidies are calculated against.
Extra help that lowers deductibles and copays — only on silver plans, only for incomes between 100% and 250% of FPL.
The 400%-of-FPL income line where ACA subsidies end entirely in 2026 — $1 over means $0 in help.
The HHS income benchmark all health-coverage assistance is measured against; 2026 coverage uses the 2025 guidelines ($15,650 single).
The annual window — Nov 1 to Jan 15 in most states — when anyone can buy or switch marketplace coverage.
Special Enrollment Period (SEP)
A personal 60-day enrollment window triggered by life events like losing coverage, marriage, birth, or moving.
An event — coverage loss, marriage, birth, move — that unlocks a special enrollment period outside open enrollment.
Metal Tiers (Bronze, Silver, Gold, Platinum)
The four ACA plan levels, defined by actuarial value — what share of average medical costs the plan pays (60/70/80/90%).
What you pay out of pocket before the plan starts sharing costs — averaging $3,786 on marketplace plans in 2026, up 37%.
The annual ceiling on what you pay for covered, in-network care — at most $10,600 per person in 2026.
Your percentage share of a medical bill after the deductible — e.g., you pay 20%, the plan pays 80%.
A fixed fee per service — e.g., $30 per doctor visit — regardless of the underlying bill.
A triple-tax-advantaged account paired with high-deductible plans — deductible going in, tax-free growth, tax-free medical withdrawals.
HDHP (High-Deductible Health Plan)
A plan meeting IRS deductible/OOPM rules that unlocks HSA eligibility — in 2026, deductibles of roughly $1,700+ single.
The right to keep your employer health plan for up to 18 months after leaving a job — at full cost plus 2%.
Cheap temporary coverage capped at 4 months under current federal rules — medically underwritten, excludes pre-existing conditions.
The no-help zone in 10 non-expansion states: income too high for Medicaid but below 100% of FPL, where subsidies begin.
How states let insurers vary premiums by age: most allow 3:1 (64-year-olds pay 3× 21-year-olds); NY and VT ban age rating entirely.
A minimal, cheap plan for under-30s (or hardship exemptions) — high deductible, three free primary visits, no subsidy eligibility.
Compare 2026 plans and prices side by side
Licensed marketplaces and brokers can show you every plan available at your address — including ones with better networks or lower deductibles than your current plan.
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