A healthcare plan is a contract between you and an insurance company that covers a defined set of medical services in exchange for regular payments called premiums. The plan spells out exactly which services are covered, how much the insurer will pay, and how much you’re responsible for when you receive care. It exists to protect you financially: without one, a single hospital stay or surgery could cost tens of thousands of dollars out of your own pocket.
How a Healthcare Plan Works
At its core, a healthcare plan pools money from many people through premiums so that the cost of expensive medical care gets spread across the group. You pay a monthly premium whether or not you use medical services that month. In return, when you do need care, the plan covers a significant portion of the bill based on the terms of your contract.
Most plans don’t start paying for your care immediately, though. You’ll typically need to hit a few cost-sharing thresholds first, and understanding these is key to knowing what you’ll actually pay.
Cost-Sharing Terms That Matter
Four numbers define how costs get split between you and your insurer: your deductible, copayments, coinsurance, and out-of-pocket maximum.
Your deductible is the amount you pay each year before your plan kicks in. If your deductible is $3,000, you’re covering the full cost of most services until you’ve spent that $3,000. Preventive care like annual checkups and immunizations is the exception: most plans cover those at no cost to you, even before you’ve met your deductible.
Once you’ve met your deductible, you start splitting costs with your insurer. A copayment is a flat fee you pay per visit or service, like $25 for a doctor’s appointment. Coinsurance is a percentage split. If your coinsurance is 20%, you pay 20% of the bill and your insurer covers the remaining 80%.
Here’s how that plays out with a real example. Say your deductible is $3,000, your coinsurance is 20%, and you rack up $12,000 in medical bills. You’d pay the first $3,000 yourself. On the remaining $9,000, you’d owe 20%, which is $1,800. Your total: $4,800.
The out-of-pocket maximum is your safety net. It’s the most you’ll pay in a single plan year, combining your deductible, copays, and coinsurance. Once you hit that ceiling, your insurer pays 100% of covered services for the rest of the year. For 2025 Marketplace plans, that cap can’t exceed $9,200 for an individual or $18,400 for a family. Plans with lower monthly premiums generally come with higher coinsurance and higher out-of-pocket limits, and vice versa.
Common Plan Types: HMO, PPO, and EPO
Healthcare plans come in several structures, and the biggest differences are about which doctors you can see and whether you need referrals.
- HMO (Health Maintenance Organization): You must use doctors, hospitals, and labs within the plan’s network, except in emergencies. You’ll choose a primary care doctor who coordinates your care and refers you to specialists. HMOs are geographically restricted, so availability depends on your home or work ZIP code. Premiums tend to be lower, but flexibility is limited.
- PPO (Preferred Provider Organization): You can see any doctor, both in-network and out-of-network, without a referral. In-network care costs less than out-of-network care, but you’re not locked in. PPOs offer the most flexibility and typically come with higher premiums.
- EPO (Exclusive Provider Organization): A middle ground. Like an HMO, you must stay in-network (except for emergencies), and out-of-network care isn’t covered. But like a PPO, you don’t need a referral to see a specialist within the network.
There’s also the POS (Point of Service) plan, which combines elements of HMOs and PPOs. You’ll have a primary care doctor and need referrals like an HMO, but you can go out-of-network at a higher cost like a PPO.
Provider Networks and Tiered Systems
Every plan maintains a network of approved doctors, hospitals, and specialists. Seeing an in-network provider always costs less than going out-of-network, and with HMO and EPO plans, going out-of-network means the plan won’t cover anything at all (outside of emergencies).
Some plans go further with tiered networks. Insurers rank providers into tiers based on cost and sometimes quality. Providers in the preferred tier have lower prices or better outcomes, and you’ll pay less in copays or coinsurance to see them. You can still visit providers in a higher-cost tier, but your share of the bill goes up. Research has found that tiered networks are associated with lower outpatient and diagnostic spending overall, since they steer patients toward more cost-effective providers while still preserving choice.
What Plans Are Required to Cover
Under the Affordable Care Act, plans sold on the Marketplace and most other individual and small-group plans must cover 10 categories of essential health benefits. These include doctor visits, inpatient and outpatient hospital care, prescription drugs, pregnancy and childbirth, mental health services, rehabilitative services, lab tests, preventive and wellness care, pediatric services including dental and vision, and emergency services.
Preventive care gets special treatment. Most plans must cover services like immunizations, cancer screenings, blood pressure checks, and well-child visits at zero cost to you, with no copay or coinsurance even if you haven’t met your deductible. This applies to in-network preventive services specifically.
Where You Get a Healthcare Plan
Most Americans get coverage through one of three main channels.
Employer-sponsored plans are the most common. Your employer selects one or more plans and typically pays a large share of the premium. According to a 2024 KFF survey, the average annual premium for employer-sponsored coverage is $8,951 for a single person and $25,572 for a family. Workers don’t pay the full amount; employers cover a substantial portion, so your paycheck deduction is usually much lower than those totals.
The Health Insurance Marketplace (sometimes called “the exchange”) is where individuals and families shop for plans if they don’t have employer coverage. It’s designed for one-stop comparison shopping across private plans in your area. If your income falls below certain thresholds, you may qualify for tax credits that lower your monthly premium. If your employer offers affordable coverage that meets minimum value standards, you generally won’t qualify for those Marketplace subsidies.
Government programs like Medicare (for adults 65 and older or those with certain disabilities) and Medicaid (for people with lower incomes) provide coverage directly. The Children’s Health Insurance Program (CHIP) covers kids in families that earn too much for Medicaid but can’t afford private insurance. You can apply for Medicaid or CHIP at any time through the Marketplace or directly through your state’s Medicaid agency.
When You Can Enroll
You can’t sign up for a healthcare plan whenever you want. The Marketplace has an annual Open Enrollment Period that runs from November 1 through January 15. Employer plans have their own enrollment windows, often in the fall.
Outside of open enrollment, you can sign up or switch plans only if you experience a qualifying life event. These include getting married, having a baby, moving to a new ZIP code, or losing existing health coverage. These triggers open a Special Enrollment Period, typically giving you 60 days to select a new plan.
Choosing Between Lower Premiums and Lower Costs at the Doctor
Every healthcare plan involves a tradeoff between what you pay monthly and what you pay when you actually use care. A plan with a low monthly premium will almost always have a higher deductible and higher coinsurance. That means you’ll pay less each month but more each time you see a doctor or fill a prescription. A plan with a higher premium flips that equation: more per month, but lower costs when you need treatment.
If you’re generally healthy and rarely visit the doctor, a lower-premium, higher-deductible plan might save you money over the course of a year. If you have ongoing health conditions, take regular medications, or are planning a major event like surgery or pregnancy, a higher-premium plan with lower cost-sharing could be significantly cheaper once you add up all your medical expenses. The key is estimating your likely healthcare usage for the year and comparing total costs, not just the premium.