What it means
In a traditional plan, the member pays a higher premium and a smaller deductible, so the insurer begins sharing costs early in the year. An HDHP flips the balance by charging less each month but expecting the member to pay the early bills out of pocket.
After the deductible is met, the plan usually pays a large share, with the member paying coinsurance up to an annual out-of-pocket maximum. For the plan to qualify for use with a health savings account, it must meet minimum deductible and maximum out-of-pocket limits that the tax authority sets and adjusts each year.
These figures change regularly, so employers and employees should check the current published numbers before enrolling. Preventive care is often covered before the deductible is reached.
The health savings account is the feature that makes an HDHP attractive. Contributions are tax-advantaged, the balance can be invested, and withdrawals for qualified medical expenses are tax-free.
Unused money stays with the member from year to year and does not disappear at year end. Employers like HDHPs because they lower the premium cost of group cover, and many put money into employees' savings accounts to offset the higher deductible.
Finance teams should compare the total cost to the company, including premiums and contributions, rather than the premium alone. When employees are healthy, the arrangement can cost the company less, but when claims rise the employees feel the pain.
The risk is that members avoid or delay care to save money, which can lead to bigger bills later. People with chronic conditions or planned surgery often find that a plan with a higher premium but a lower deductible costs them less over the year.
A sound choice depends on expected medical use, not only on the monthly premium. A useful way to compare is to add the premium to the amount the member would pay in a realistic year of care, and test the result in both a healthy year and a bad one.
The plan that costs less across both scenarios, after allowing for any employer contribution and tax savings, is usually the better fit.
In practice
Real-world examples
Example 1
A 28-year-old software developer with few medical needs chooses an HDHP with a premium that is $2,400 a year cheaper than the alternative. She pays the savings into a health savings account and keeps the balance growing for future years.
Example 2
A small manufacturing company moves staff to an HDHP and puts $1,000 into each employee's savings account. Total spending on health cover falls, and the finance director tracks claims and satisfaction each quarter to see whether people are skipping care.
Example 3
A couple expecting a baby compares plans and sees that they will certainly reach the out-of-pocket limit. They choose the plan with the lower deductible and higher premium, because the HDHP's lower premium would be outweighed by the early medical bills.
Think of it
An HDHP is like comprehensive car insurance with a very high excess fee. You pay a lower monthly fee for the policy, but if you have a minor scratch, you pay for it yourself. Insurance only steps in for major accidents that exceed your high excess.
Formula
Calculation
Total annual cost = annual premium + member share of medical bills
Member share = deductible + (coinsurance rate x (medical bills - deductible)), capped at the out-of-pocket maximum
Suppose an HDHP has an annual premium of $4,800, a deductible of $3,000, coinsurance of 20% and an out-of-pocket maximum of $5,000. In a year with $10,000 of medical bills, the member pays 3,000 + 0.20 x (10,000 - 3,000) = 3,000 + 1,400 = $4,400, which is below the $5,000 cap. Total annual cost is 4,800 + 4,400 = $9,200.Case study
Seen in the real world
Northgate Design Studio is an illustrative, fictional business with 45 employees that offered a traditional health plan costing $7,200 per employee a year. The owner switched to an HDHP costing $4,800 and deposited $1,200 into each employee's savings account, a saving to the company of 7,200 - 4,800 - 1,200 = $1,200 per person, or $54,000 across all staff.
In the first year, most employees spent less than expected, but two had large medical bills. The studio added a one-off contribution for those employees and held a workshop on how the savings account works.
The illustrative lesson is that an HDHP can cut cost, but only when the employer pairs it with contributions and clear communication. Otherwise the saving falls on the company while the burden falls on the employees who are least able to bear it.
Watch out
Common mistakes
- Choosing an HDHP purely for the lower premium without estimating likely medical costs for the year.
- Forgetting to open or fund the health savings account, which leaves the member exposed to the full deductible and misses the tax advantage.
- Assuming the deductible and out-of-pocket limits stay the same each year, when the tax authority adjusts the qualifying figures regularly.
Questions
People also ask
What is the difference between a deductible and an out-of-pocket maximum?
The deductible is what you pay before the insurer starts sharing costs, while the out-of-pocket maximum is the most you can pay in a year including coinsurance.
Can anyone with an HDHP use a health savings account?
Generally only if the plan meets the qualifying rules and the person has no other disqualifying cover, so the details should be checked with the plan provider.
Is preventive care covered before the deductible?
Most plans cover defined preventive services before the deductible, though what counts as preventive varies, so the plan documents should be read.