Insurance is one of those things that you need to budget for when going to Disney World. While travel agents tend to make you book your travel insurance there and then, you don't need too. They might tell you it's a condition of booking, but you can just say you already have insurance lined up or you have an annual policy already. It's big business for travel agents, so don't feel forced into buying it from them unless you're happy with their cover and price.
Some people don't bother with travel insurance when going abroad at all. While there is a cost benefit analysis to the decision, when we're dealing with the U.S.A. it is highly recommended you get covered, even for medical reasons alone.
America doesn't have a health system quite like the NHS as we do. For people who have never been abroad, it's taken for granted that we don't have to directly pay for our medical care. However, it's not like that everywhere else. American hospitals are privately owned and you pay for the treatment you need, or have adequate health insurance. America is a society where you have your own freedom to pay for your own medical cover, or risk it. While here in the UK we pay National Insurance which contributes towards the funding of our NHS.
For very minor things, Disney does have on-site medical staff who can assist you, but if you ever need a trip to a doctor, or worse - an ambulance - you'll be responsibility for high medical bills if you're without insurance.
Florida has regular hurricanes that can severely disrupt flights and parts of your holiday. In fact, if you go the second half of the year you're almost guaranteed to make contact with at least a tropical storm.
I know it's an absolute nightmare to even think you'd need to cancel your Disney World holiday, but life happens and sometimes you might have to. Getting cover right away covers you if you need to cancel. Don't wait until the last minute to book your travel insurance because you can't cancel for reasons that happened before taking out the cover.
Depending on the length of stay, you can get standard 2-week cover starting at around £60 per person. Adding more cover like excess protection, gadget cover etc will bring it up, but it's up to you how much cover you think you need. Having medical conditions does bring your premiums up quite a bit, and those need to be declared when you're taking out the cover. We list some providers below who might help you.
Having medical conditions does increase the price, but it's best not to lie. Make sure anything you have been officially diagnosed with your GP or doctor is listed, and anything you take medication for. You don't want to give them any excuse not to pay out if you need help, even if it means your premiums are a little higher.
Picking A Provider
It's always best to shop around when it comes to insurance, and if you rely on your bank or credit card cover, please make sure it has adequate cover, as those policies tend to not cover everything or have high excesses. I list some providers below I've had direct and indirect experience with.