Private Medical Insurance — Explained
What is underwriting?
Underwriting is the process insurers use to decide what medical conditions your policy will and won’t cover. It forms one of the most important parts of private medical insurance (PMI), because it determines how pre-existing medical conditions are handled both now and in the future.
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When you apply for health insurance, the insurer assesses your medical history using a chosen underwriting method. This helps them understand whether certain conditions should be excluded immediately, reviewed later, or potentially covered in the future depending on your health history.
WHAT IS IT?
Underwriting at a glance
Underwriting exists because private medical insurance is designed primarily to cover new conditions that arise after your policy begins, rather than medical issues you already knew about beforehand.
There are several underwriting methods available in the UK market, but the two most common are Moratorium underwriting and Full Medical Underwriting (FMU).
With Moratorium underwriting, you usually won’t need to provide your full medical history upfront. Instead, pre-existing conditions are automatically excluded at the start of the policy. In many cases, those conditions may become eligible for cover later if you remain symptom-free, treatment-free, medication-free, and advice-free for a continuous period — typically two years.
Full Medical Underwriting works differently. You disclose your medical history when applying, and the insurer assesses this information before the policy starts. They will then confirm exactly which conditions are covered, excluded, or subject to special terms from day one.
Some insurers also offer Continued Moratorium (CMORI) underwriting when switching from another provider, allowing existing moratorium time already served to be recognised rather than restarted.
IN PLAIN ENGLISH
Underwriting is the insurer’s way of deciding how your past medical history affects your cover. It determines which conditions can be claimed for, which may be excluded, and whether certain conditions could become covered in the future.
How it fits into your policy
Underwriting affects every future claim you make. Before approving treatment, insurers review whether the condition is considered new, related to a previous condition, or falls within any exclusions applied under your underwriting terms.
This is why choosing the right underwriting method is important. Moratorium underwriting can make joining simpler and faster, while Full Medical Underwriting can provide greater clarity upfront about what is and isn’t covered.
Neither method is universally “better” — the right option depends on your medical history, your priorities, and how much certainty you want at the start of the policy.