Health insurance
How does medical underwriting work?
The short answer
Medical underwriting is how an insurer decides which of your past health problems it will cover. The two common approaches are moratorium underwriting, which automatically excludes recent conditions for a set period, and full medical underwriting, where you declare your history upfront and the insurer lists exclusions before you buy.
Written by Emma Leadbetter. Reviewed by Stuart Hendy.
Published 2026-09-14. Last reviewed 2026-09-14. Next review due 2027-03-14.
Why underwriting exists
Private medical insurance covers conditions that arise after cover starts. Underwriting is the process that draws the line between what counts as new and what counts as pre-existing. The approach you choose at the outset shapes every claim you make afterwards. [1]
Moratorium underwriting
With moratorium underwriting you answer no medical questions when you apply. Instead, anything you had symptoms, medication, advice or treatment for in a defined look-back period is excluded. If you then go a continuous period without any of those, the condition can come back into cover.
Full medical underwriting
Here you declare your medical history when you apply. The insurer reviews it and writes any personal exclusions into your certificate before you buy, so you know where you stand from day one. It takes longer to set up and it asks more of you at application.
| Moratorium | Full medical underwriting | |
|---|---|---|
| Medical questions at application | None | Full declaration |
| When exclusions are known | At claim | Before you buy |
| Can excluded conditions return to cover | Yes, after a clear period | Usually no, unless the insurer reviews it |
| Speed to set up | Fast | Slower |
| Effect on premium | Set from the insurer’s standard rates for your age and cover | Rated on your declared history, so it can be higher or the same |
What this means at claim time
An insurer can ask your GP for records when you claim, and can decline a claim that falls inside an exclusion. Answering questions incompletely can also allow an insurer to change or void a policy, so accuracy at application matters. If you disagree with a decision, you can complain and then take it to the Financial Ombudsman Service. [2]
Common questions
- Which is better, moratorium or full medical underwriting?
- Neither is better in the abstract. Moratorium is quicker and asks nothing at application, but you only learn what is excluded when you claim. Full medical underwriting takes longer and tells you where you stand before you buy.
- How far back does a moratorium look?
- Most UK insurers use a five-year look-back for symptoms, medication, advice or treatment, and most restore cover for a condition after a continuous clear period. The exact periods are set by your policy wording, so check it rather than assuming.
- What happens if I get a medical question wrong?
- An insurer can change, cancel or void a policy and decline a claim where information was incomplete or wrong. If you disagree with the decision, complain to the firm and then take it to the Financial Ombudsman Service, which is free to use. [2]
Sources
- Association of British Insurers. Insurers process record £4bn across individual and workplace health schemes (2024 data). 21 January 2026 (primary source)
- Financial Ombudsman Service. Complaints about medical insurance. Accessed 14 September 2026 (primary source)