Health Cover
Excess, co-payment and co-insurance are three different bills
Health policies share cost with you in three distinct ways, and a quote can be cheap because it uses all three at once.
The options around cost sharing in health cover are set out side by side below, with the conditions that genuinely favour one over the other.
The difference in one place
- An excess is a fixed sum you pay before the insurer pays anything.
- A co-payment is a fixed amount per item of treatment, repeated each time.
- Co-insurance is a percentage of every bill, which is unbounded unless capped.
The excess comes first
An excess is the amount you meet before the policy responds, and on health cover it is usually applied per policy year rather than per claim. Some wordings apply it per condition instead, which means a year with two unrelated illnesses costs two excesses.
That single word, per year or per condition, can double your exposure without changing the headline number. It is stated in the schedule and is one of the most commonly misread fields on a health quote.
A co-payment repeats
A co-payment is a fixed contribution per consultation, per scan or per prescription, and it applies every time. Unlike an excess, it never stops being charged, so a long treatment course accumulates many small payments. Ten outpatient appointments at a modest co-payment can quietly exceed a substantial one-off excess.
Multiplying the co-payment by a realistic number of appointments is the only honest way to compare it against an excess.
Co-insurance is a percentage
Co-insurance means you pay a stated share of every covered cost, commonly ten or twenty per cent. On a small outpatient bill that is trivial, and on a large inpatient episode it is not.
Twenty per cent of a major surgical admission is a serious number, which is why an annual out-of-pocket cap matters so much. A co-insurance policy without a cap leaves your maximum exposure undefined, which is the opposite of what insurance is for.
Why insurers use them
Cost sharing reduces claim frequency because people weigh whether a visit is necessary when part of the cost is theirs. It also removes small claims whose administration costs more than the benefit. Both effects lower the premium genuinely, so the discount is real rather than a trick.
The question is only whether the sharing arrangement matches how you would actually use the policy.
Comparing quotes that use different mechanisms
Model two scenarios: one bad year with a major admission, and one ordinary year with several outpatient appointments. Run both through each quote and the true cost difference appears immediately. A policy with a high excess wins the ordinary year and can lose the bad one, or the reverse, depending on structure.
Where it helps most, this exercise takes ten minutes and is more informative than any comparison table.
None of this is a substitute for talking to a clinician if something feels wrong.
The cap is the term to look for
An annual out-of-pocket maximum limits everything you can be asked to contribute in a policy year. Where it exists, it converts an open-ended co-insurance arrangement into a bounded one.
Where it does not, the worst case is bounded only by the size of the medical bill. Which structure suits your circumstances is a question for a regulated adviser rather than a general rule.
Side by side
| Consideration | What it means in practice |
|---|---|
| The excess comes first | An excess is a fixed sum you pay before the insurer pays anything. |
| A co-payment repeats | A co-payment is a fixed amount per item of treatment, repeated each time. |
| Co-insurance is a percentage | Co-insurance is a percentage of every bill, which is unbounded unless capped. |
The takeaway
Work out your worst-case total contribution, not the premium. That is the number that matters.
Pick the one that costs you least, and let the rest wait.
Questions readers ask
Is a higher excess always cheaper overall?
Only if you claim rarely. Model an ordinary year and a bad year before choosing, because the excess that wins one can lose the other.
Do co-payments count towards my excess?
Often not, and the two can apply together. Check whether the wording treats them as separate contributions, because assuming they merge is a common error.
