Stressed,
This really depends on whether you currently HAVE health insurance or not.

If you have health insurance through your employer, you had generally get a continuation of coverage without any exceptions for pre-existing conditions. Most employers will be required to offer the initial form of continuing coverage - called COBRA coverage - to you for a limited period of time. Once your COBRA coverage expires, you will be eligible for a guaranteed issue policy under HIPAA - you just have to contact any local health insurance provider, request a HIPAA policy, and show proof that you had COBRA coverage and that it expired.

This isn't always an option for very small businesses - which aren't necessarily required to offer COBRA coverage - but the laws of your particular state may provide additional assistance on health insurance continuity.

On the other hand, if you're not currently covered at all and are looking to get health insurance coverage, you'll have to contact the insurance companies and ask them how they will treat any pre-existing conditions or surgeries that you may have. Some insurance companies treat health issues differently than others (depending on the health concern), so ask more than one company if you're not getting a favorable response. Depending on the state you live in, there may also be additional state programs to help you receive some type of health coverage.

I hope that helps a little!