On April 21, Google will begin rolling out an update to its search algorithm that could have a huge impact on your hospital’s SEO.

Google tweaks its algorithm around 600 times every year (665 times in 2012) as it attempts to deliver better search results. Most of those tweaks are unheralded changes to small variables that you probably don’t even notice, either as you search or as you monitor your SEO, but this forthcoming update, which will determine whether sites are mobile-friendly and adjust their rankings accordingly, will have a bigger (perhaps significantly so) impact than any of them, including the Panda and Penguin updates.

As far as major algorithms go, this one is pretty straightforward: Every site Google crawls is either mobile-friendly or not. There are no shades of gray, no murky middle ground. If you’re in the former camp, great! You don’t have to worry about what will happen to your incoming traffic next month—you may even get a boost. But if you’re in the latter camp, the time to start making a plan for the future of your website is now.

If you’re not sure whether your website or blog is mobile-friendly, don’t worry—you can find out in seconds. Google results already show you whether a site is mobile-friendly or not, so the easiest way is to do a Google search for your hospital on a mobile device. If Google gives you the thumbs-up, you’ll see a mobile-friendly badge below the URL like the one below.

There’s also a convenient mobile-friendly test on Google’s Developers site that accepts any URL as input and spits a status back out almost instantly. If the tool says that your site isn’t mobile-friendly, it’ll also give you a checklist of problems it detected and links to a number of resources to help you fix them, whether your site was hard-coded or built with a content management system.

What to do if Google says you’re not mobile-friendly

Every site is different. There are many factors that determine whether one is mobile-friendly or not, but the most important ones are links that are too close together and difficult to tap on a touchscreen, text that’s too small and unreadable without pinching to zoom in, content that’s wider than the screen and not viewable in full without scrolling form side to side, and not having a mobile viewport, which tells a page to render itself for a smaller screen instead of a full-sized web browser.

If you’re able to fix any problems Google identifies, then you absolutely must do so by April 21. Failing to do so could lead to a significant loss of inbound traffic if you fall down Google’s rankings. Even worse, users very well could end up on your competitors’ sites instead.

If you’re still using a site that simply wasn’t designed to be used on mobile devices, however, you might not have an alternative to replacing it. Maybe it hasn’t been an priority, or maybe you haven’t been able to get the CFO on board with the expenditure. In the latter case, the algorithm changes might be just what you need to convince your higher-ups that it’s time to upgrade.

There’s a lot that goes into redesigning and launching a website, so you probably won’t be able to finish your project by the time the update goes live on April 21. It’s not all bad news, though, because Google recently confirmed that the new algorithm will work on a page-by-page basis. That means you can focus your efforts on the most important pages of your website, making sure they’re mobile-friendly before tackling the whole thing.

There’s no doubt that the update will have a significant impact on search rankings for hospitals around the country, but with the right plan, you can minimize the impact on your own or even take advantage of the impact on competitors who aren’t mobile-friendly.