Key insurance terms that start with "I"

A process to resolve disputes between patients and health plans or providers about coverage decisions or billing. An independent arbitrator reviews the case and makes a binding decision. This process protects patients from denied claims and surprise bills.

Income verification is the process the Marketplace uses to confirm the household income you reported on your application. Your estimate determines your subsidy, so the Marketplace checks it against IRS and Social Security data before finalizing your eligibility.

Most applications clear automatically. If the figure you entered differs meaningfully from what federal records show, you'll receive a Data Matching Inquiry (DMI) asking for documentation, usually within 90 days.

Documents that typically satisfy a request:

• Recent pay stubs
• Your most recent federal tax return
• A signed letter from an employer stating wages
• Self-employment records: profit and loss statements, 1099s, or bookkeeping ledgers
• Social Security or unemployment benefit award letters

Missing the deadline matters. If you don't respond, the Marketplace can reduce or end your Premium Tax Credit, which means your monthly premium jumps to the full unsubsidized amount.

Income verification carries more weight starting with the 2026 tax year because caps on Advance Premium Tax Credit repayment were eliminated. If you underestimate your income and receive more credit than you were entitled to, you now repay the full excess to the IRS rather than a limited portion.

This is the hardest part of the process for anyone with variable income: freelancers, contractors, seasonal workers, and anyone whose earnings include commissions or investment gains. A conservative estimate plus prompt mid-year updates is the practical defense. If your income changes, report it to the Marketplace right away rather than waiting for tax season.

A penalty you had to pay if you didn't have health insurance coverage under the ACA's individual mandate. The penalty was calculated as a percentage of income or a flat amount per person, whichever was higher. The penalty was reduced to zero starting in 2019.

A provision of the Affordable Care Act that required most Americans to have health insurance or pay a penalty. The individual mandate penalty was reduced to zero in 2019, so there is currently no penalty for being uninsured, but the requirement technically still exists in some states.

Individual health insurance is a plan you purchase for yourself (and optionally your dependents) on your own — not through an employer. You’re responsible for the full premium, though you may qualify for an Advance Premium Tax Credit (APTC) to reduce your monthly cost if you enroll through the ACA Marketplace.

Individual health insurance is the right path if you are:

• Self-employed or a freelancer
• Between jobs or recently lost employer coverage
• Working part-time and not offered employer benefits
• An early retiree not yet eligible for Medicare
• A dependent aging off a parent’s plan

Individual plans purchased through the ACA Marketplace are the only way to access Premium Tax Credits and Cost-Sharing Reductions. Plans bought directly from an insurer off-Marketplace are ACA-compliant but subsidy-ineligible.

Individual coverage is regulated differently than group/employer coverage — insurers cannot charge you more or deny coverage based on pre-existing conditions on ACA-compliant plans.

In-network refers to doctors, hospitals, labs, and other health care providers that have a contract with your insurance plan. That contract sets the rates your insurer will pay, which is why in-network care costs significantly less than out-of-network care.

When you use an in-network provider:

• Your insurer has pre-negotiated rates with them
• Your deductible, copays, and coinsurance apply at the lower in-network rate
• The care counts toward your in-network out-of-pocket maximum

Before scheduling any appointment, confirm the provider is in-network with your specific plan — not just your insurer. A doctor can be in-network for one plan but out-of-network for another from the same company. Always verify using your plan’s provider directory or by calling the provider directly.

On HMO and EPO plans, using in-network providers isn’t just cheaper — it’s required for coverage (except emergencies). On PPO and POS plans, you can go out-of-network but will pay more.