Key insurance terms that start with "C"

Prescription drug coverage that's considered 'good enough' for Medicare purposes. If you have creditable drug coverage from an employer or other source, it counts toward Medicare Part D eligibility. You won't face a penalty if you enroll in Part D later.

The process when you have more than one health insurance policy. The plans coordinate to avoid paying more than 100% of your costs. Your primary insurance pays first, and your secondary insurance covers the remaining portion (up to what it normally covers).

Health insurance coverage that qualifies as acceptable coverage under the Affordable Care Act. If you have creditable coverage, you may not be eligible for subsidies on the health insurance marketplace. It includes employer plans, government programs, and other qualified plans.

Covered services are the medical treatments, procedures, prescriptions, and other health care items that your insurance plan will pay for (subject to your cost-sharing obligations). A service being “covered” means it’s included in your plan’s benefits — not that it’s free. You’ll still typically pay your deductible, copay, or coinsurance for covered services until you reach your out-of-pocket maximum.

Under the ACA, all Marketplace plans must cover the 10 Essential Health Benefits as a minimum baseline. Beyond that, plans vary in what additional services they cover.

The fastest way to check whether a specific service is covered is your plan’s Summary of Benefits and Coverage (SBC) or Evidence of Coverage (EOC). For services not listed, call your insurer’s member services before receiving care — never assume a service is covered without verifying.

Coverage also depends on context: a service may be covered when delivered by an in-network provider but not when out-of-network, or covered for one diagnosis but not another. Prior authorization requirements can also affect whether a technically covered service is paid for in a given situation.

The amount of health care costs you pay yourself, separate from your premium. Cost sharing includes copays, coinsurance, and deductibles. The more you pay in cost sharing, the lower your monthly premium is typically. Different plans have different cost-sharing structures.

COBRA (Consolidated Omnibus Budget Reconciliation Act) is a federal law that gives you the right to continue your employer-sponsored health insurance for a limited time after losing coverage due to a qualifying event — such as leaving a job, being laid off, having your hours reduced, or losing coverage as a dependent.

COBRA coverage is identical to your prior employer plan — same network, same benefits, same cost-sharing. The catch: you pay the full premium yourself, including the portion your employer previously covered. This often makes COBRA significantly more expensive than alternatives.

COBRA continuation periods by event type:

• Job loss or reduced hours: up to 18 months
• Dependent losing coverage (divorce, death of covered employee, age 26): up to 36 months
• Medicare entitlement: up to 36 months for dependents

You have 60 days from receiving the COBRA election notice to enroll, and coverage is retroactive to the date you lost original coverage. This means you can wait and see if you need care before committing — but you’ll owe back premiums if you do enroll retroactively.

The Children’s Health Insurance Program (CHIP) provides low-cost health coverage to children in families who earn too much to qualify for Medicaid but can’t afford private insurance. In most states, CHIP also covers pregnant women. CHIP is jointly funded by the federal government and states, and eligibility rules vary by state.

CHIP covers a comprehensive set of services including:

• Routine checkups and immunizations
• Doctor and specialist visits
• Prescriptions
• Dental and vision care
• Emergency services
• Inpatient and outpatient hospital care
• Mental health services

Unlike Marketplace plans, CHIP accepts applications year-round — there is no Open Enrollment Period. If your child qualifies, they can be enrolled at any time.

CHIP eligibility is based on household income as a percentage of the Federal Poverty Level. The income threshold varies by state but generally covers families earning up to 200%–300% FPL. Premiums, if any, are very low. Some states charge no premium at all.

A Catastrophic health plan is a type of ACA health insurance designed to protect against worst-case medical scenarios at the lowest possible monthly premium. It is only available to people under 30, or adults of any age who qualify for a hardship or affordability exemption.

Catastrophic plans have the highest deductibles of any ACA plan type — equal to the federal out-of-pocket maximum for the year ($9,200 for individuals in 2026). Before you meet that deductible, you pay 100% of most medical costs out-of-pocket. Three primary care visits per year are covered before the deductible, and all ACA-required preventive services are covered at $0.

Important limitations compared to metal tier plans:

• Catastrophic plans do not qualify for Premium Tax Credits, so you pay the full premium
• They are not available on the standard Marketplace plan selection screen — you must apply for an exemption first
• Cost-Sharing Reductions do not apply

For most people under 30, comparing a Bronze plan (which does qualify for APTC) to a Catastrophic plan will reveal the Catastrophic plan is only cheaper if you don’t qualify for any subsidy. Run the comparison before assuming Catastrophic is your lowest-cost option.

A Cost-Sharing Reduction (CSR) is a discount that lowers what you pay out-of-pocket when you use health care — your deductible, copays, and coinsurance. CSRs are only available on Silver plans, and only if your household income is between 100% and 250% of the Federal Poverty Level (FPL).

If you qualify, your Silver plan effectively acts like a Gold or Platinum plan. A standard Silver plan covers about 70% of costs, but with CSR, your plan could cover 73%, 87%, or 94% of costs depending on your income level — meaning your deductible drops and your copays shrink significantly.

CSR is automatic when you qualify — but only if you pick Silver. If you choose a Bronze or Gold plan instead, you lose the CSR benefit entirely, even if you're eligible. This makes Silver plans the clear choice for most families in the 100%–250% FPL range.

One important note for 2026: the enhanced premium subsidies that temporarily expanded CSR eligibility expired December 31, 2025. Income limits are back to standard thresholds.

A copay is a fixed dollar amount you pay for a specific health care service at the time of your visit. Your insurance covers the rest. Copay amounts are set by your plan and vary by service type.

Common copay examples:

• Primary care visit: $20–$40
• Specialist visit: $40–$70
• Urgent care: $50–$100
• Emergency room: $100–$350
• Generic prescription: $5–$15

Copays may apply before or after your deductible depending on the service and your plan. Many plans cover primary care and prescriptions with a copay even before you’ve met your deductible — but confirm this in your plan’s Summary of Benefits and Coverage.

Copays count toward your out-of-pocket maximum. Once you hit that limit, you typically pay $0 for covered services for the rest of the year.

Coinsurance is your share of a medical bill expressed as a percentage. After you’ve met your deductible, you and your insurance company split the cost of covered services — your portion is the coinsurance.

For example: your plan has 20% coinsurance. You see a specialist and the bill is $400. Your insurance pays $320 (80%) and you pay $80 (20%). That $80 is your coinsurance.

Coinsurance rates vary by plan tier and service type. Typically:

• Bronze: You pay 30–40% coinsurance
• Silver: You pay 20–30%
• Gold: You pay 10–20%
• Platinum: You pay 5–10%

Like copays, your coinsurance payments count toward your out-of-pocket maximum. Once you reach that limit, your plan covers 100% of covered costs for the rest of the year.