Two policies from different insurers can look almost identical on price and headline cover, then behave completely differently the moment you actually need to claim for something you had symptoms of before you took the policy out. The reason is underwriting — the process an insurer uses to decide what it will and won't cover for you personally. In the UK, most individual health insurance policies use one of two approaches.
Moratorium underwriting
This is the simpler option to apply for. You don't need to disclose your full medical history up front. Instead, the insurer automatically excludes any condition you've had symptoms of, tests for, or treatment for in a set period before the policy starts — typically the five years immediately before. If you stay symptom-free and treatment-free for that condition for a continuous period, usually two years, while the policy is in force, it can then become covered automatically, without you needing to do anything.
The appeal is speed and simplicity: no lengthy medical questionnaire, and cover can often start the next day. The trade-off is less certainty at the outset about exactly what's excluded, since it depends on your medical history rather than a fixed list agreed at the start.
Full medical underwriting
Here, you disclose your full medical history in detail when you apply. The insurer reviews it and tells you upfront, in writing, exactly what (if anything) is excluded — a process sometimes called 'moratorium to personal medical exclusions'. This gives you certainty from day one about exactly where you stand, which can matter a lot if you have a specific pre-existing condition you want clarity on before committing to a policy.
The trade-off is time and effort: the application process is longer, and you may need to request medical records from your GP, which can take weeks. Some insurers charge a fee for this, others don't.
Note: Group/employer-provided health insurance sometimes uses a simpler 'medical history disregarded' basis, where prior conditions are covered from day one for scheme members — check your specific scheme rules rather than assuming individual-policy rules apply.
Compare underwriting approaches side by side — See how Bupa, AXA Health, Aviva, Vitality and other leading UK insurers approach underwriting — free, no-obligation comparison.
Which should you choose?
If you're broadly healthy and want cover in place quickly with minimal admin, moratorium underwriting is usually the more practical route. If you have a specific past condition and want written confirmation of exactly where you stand before you commit — for example because you're planning treatment for something you've had before — full medical underwriting gives you that certainty. See our insurer reviews for how each provider handles both routes, or read about pre-existing conditions and health insurance in more detail.
Frequently asked questions
Which is cheaper — moratorium or full medical underwriting?
Neither is inherently cheaper; the premium depends on the insurer, your age, location and cover level either way. The real difference is in what's excluded and how quickly that's confirmed, not the headline price.
Can I switch from moratorium to full medical underwriting later?
Some insurers allow this, sometimes called 'moratorium to continued personal medical exclusions' conversion, but it varies by provider and isn't universal — check with a specific insurer or ask during comparison.
Does underwriting type affect claims for new conditions?
No — both underwriting types cover new conditions that arise after the policy starts in the same way. The difference is purely about how pre-existing conditions from before the policy began are treated.
Related reading
- Pre-Existing Conditions and Health Insurance: What's Covered, What Isn't
- Why Are Private Health Insurance Premiums Rising in 2026?