Most American families don't pick a health insurance plan. They inherit one. It comes from an employer, gets auto-renewed every year, and only gets a second look when something goes wrong — a surprise bill, a denied claim, a doctor who suddenly isn't covered.

That's a costly habit. The average family premium for employer-sponsored coverage has climbed past $25,000 a year, according to the Kaiser Family Foundation's annual employer survey, with workers covering roughly $6,500 of that directly. When you're spending that much, the difference between a good plan and a mismatched one can run into thousands of dollars a year.

Here's how to actually run the numbers, whether you're choosing among employer plans, shopping the ACA marketplace, or weighing COBRA against something new.

Start With Your Family's Real Medical Spending, Not the Worst Case

The single biggest mistake people make is choosing a plan based on a catastrophe that probably won't happen. Yes, you want protection against a $500,000 hospital bill. But most families' actual spending is boring: checkups, prescriptions, a couple of urgent care visits, maybe therapy or a specialist.

Pull your last 12 months of explanation of benefits statements — the EOBs your insurer mails or posts online. Add up what you actually paid out of pocket, not what was billed. That number, not a hypothetical, is your baseline.

Then ask one question: would a high-deductible plan have cost me less? A family with $1,200 in annual spending often comes out ahead on a high-deductible plan paired with a health savings account, because the premium savings exceed the extra out-of-pocket costs. A family managing a chronic condition like diabetes or Crohn's disease usually won't — they'll hit the deductible every year anyway, so a lower-deductible plan with higher premiums often wins.

If chronic conditions or mental health care are part of your family's picture, it's worth understanding how coverage for those services actually works before you compare plans. Our guide to mental health care access and warning signs covers what to look for in a plan's behavioral health benefits.

The Four Numbers That Decide Everything

Every plan comes down to four figures. Learn them and you can compare any two plans in about ten minutes.

1. Premium

What you pay monthly, whether or not you use care. In 2024, the average ACA marketplace premium for a family of four was roughly $1,400 a month before subsidies, according to KFF. Employer coverage runs lower for the worker but costs the employer far more.

Don't stop at the premium. A plan with a $400 monthly premium and a $12,000 deductible can cost more than a $700 premium plan with a $3,000 deductible if anyone in your family needs real care.

2. Deductible

What you pay before most coverage kicks in. Family deductibles are typically double or triple individual ones. Watch for "embedded" versus "aggregate" deductibles — with an embedded deductible, one family member hitting their individual limit triggers coverage for that person even if the family total hasn't been met. With an aggregate deductible, the whole family has to hit the combined number first. Embedded is almost always better.

3. Coinsurance

Your share of costs after the deductible. An 80/20 plan means you pay 20 percent of the bill until you hit the out-of-pocket max. On a $30,000 surgery, that 20 percent is $6,000.

4. Out-of-Pocket Maximum

Your worst-case number for covered, in-network care. Under the Affordable Care Act, this can't exceed $9,450 for an individual or $18,900 for a family in 2024. This is the number that actually protects you. A plan with a $9,000 out-of-pocket max is a fundamentally different product than one with a $4,000 max, even if the premiums look similar.

If you only remember one thing: add your annual premium to your out-of-pocket maximum. That's the true worst-case cost of any plan. Compare that number across plans, not the premiums alone.

Check the Network Before You Check the Price

A cheap plan that doesn't cover your pediatrician is expensive. Network is where most families get burned.

Before enrolling, verify three things in writing:

  • Your primary care doctor and each child's pediatrician are in-network.
  • Any specialists your family sees regularly — allergists, endocrinologists, psychiatrists — are in-network. Mental health providers are especially likely to be out-of-network, even on plans that technically cover behavioral health.
  • Your preferred hospital and its affiliated labs and imaging centers are in-network. A hospital can be in-network while the radiologist reading your scan is not, which is how a $200 MRI becomes a $1,800 bill.

Ask the insurer directly, get the answer in writing, and check again after January 1 — networks change annually, and doctors get dropped mid-year more often than most people realize.

HSA, FSA, or Neither: The Tax Side of the Decision

If you choose a high-deductible health plan, you may be eligible for a health savings account. HSAs are triple tax-advantaged: contributions are pre-tax, growth is tax-free, and withdrawals for qualified medical expenses are tax-free. In 2024, families could contribute up to $8,300. Unused HSA money rolls over year after year and stays with you even if you change jobs — unlike a flexible spending account, which is use-it-or-lose-it.

An FSA still makes sense if your employer offers one and you have predictable expenses like braces or regular prescriptions. But estimate carefully. The average FSA forfeiture runs a few hundred dollars per household, and that's money you simply lose.

The math gets messier if your family is managing a chronic condition where treatment costs are already high. Our reporting on heart-healthy diets recommended by cardiologists is a reminder that prevention spending — nutrition counseling, preventive screenings, gym memberships — is often covered at 100 percent before the deductible. Use those benefits. They're the cheapest care you'll ever get.

Where to Buy Coverage If You Don't Have an Employer Plan

Roughly half of Americans get coverage through an employer. The rest navigate a patchwork that includes the ACA marketplace, Medicaid, Medicare, and direct purchase.

If you're buying on Healthcare.gov or a state exchange, the key move is checking whether you qualify for subsidies. The enhanced subsidies that expanded eligibility beyond 400 percent of the federal poverty line have been extended repeatedly by Congress, and millions of families now pay less than 8.5 percent of income for a benchmark plan. Skipping the subsidy check is the most common and most expensive mistake marketplace shoppers make.

If you're leaving a job, COBRA lets you keep your old plan for up to 18 months — but you pay the full premium plus a 2 percent administrative fee. A plan that cost you $500 a month at work can cost $1,800 on COBRA. Compare that against a marketplace plan before you sign.

If you're between jobs or self-employed, short-term health plans look cheap but often exclude pre-existing conditions, maternity care, and mental health coverage. Read the exclusions page before you buy. The savings evaporate fast if anyone in the family needs actual care.

A Practical Checklist for Open Enrollment

Open enrollment for most employer plans runs in the fall, and ACA marketplace enrollment typically opens November 1. Here's what to do before you click submit:

  • Add up last year's actual out-of-pocket spending. Use EOBs, not guesses.
  • For each plan, calculate premium × 12 + out-of-pocket maximum. That's your worst-case number.
  • Confirm your doctors, hospitals, and any specialists are in-network for the coming year.
  • Check whether prescriptions your family takes are on the plan's formulary, and at what tier.
  • Compare the HSA option against the traditional plan using your real spending number.
  • If buying on the marketplace, run the subsidy calculator before browsing plans.
  • Read the summary of benefits and coverage — a standardized four-page document every plan must provide. It's the fastest way to compare two plans side by side.

One more consideration that trips up families: dependents. Under the ACA, children can stay on a parent's plan until age 26, but if you have a child in another state for college, check whether the plan's network covers providers there. A student who gets sick 800 miles from home on an HMO with a narrow local network is in for a bad semester.

Insurance decisions feel overwhelming because the industry designs them to. But the underlying math is simple: premium plus out-of-pocket max is your ceiling, actual spending is your floor, and the network is the wild card. Get those three right and you'll almost always land on the plan that fits your family — not the one that just happens to be the default.