If you've been paying attention to Xbox rumors and announcements of late, you may know that Xbox Live Gold and Xbox Game Pass have now been officially merged into a single $15 a month Xbox Game Pass Ultimate subscription plan (which now also includes PC games , for good measure).

What you might not realize is you can upgrade up to three years of a current Xbox Live gold subscription to the new, more expensive plan for $1 as part of a launch promotion from Microsoft.

As Microsoft describes on the Xbox Game Pass Ultimate announcement page (emphasis added):

New members and existing Xbox Live Gold and Xbox Game Pass for Console members can join or upgrade today and get their first month for just $1. Additionally, if you're a current Xbox Live Gold or Xbox Game Pass member, and have prepaid months on your account, you'll get Xbox Game Pass Ultimate credit for those months when you upgrade.

The offer is confirmed again on the upgrade page itself, which notes when you make the purchase, "Joining Xbox Game Pass Ultimate will upgrade your remaining Xbox Live Gold or Xbox Game Pass membership(s) into Xbox Game Pass Ultimate for the same amount of time, up to 36 months total." Only after your current prepaid subscription time has expired will Microsoft start charging the usual $15 monthly fee.

Don't have an Xbox Live Gold subscription yet (or want to extend it a bit)? We've confirmed that you can buy an Xbox Live Gold digital code to add time to your account before you make use of the $1 conversion to Game Pass Ultimate. That effectively means you can prepay for three years of Game Pass Ultimate for just $181, compared to what would usually cost $540 in monthly subscription fees.

Since launching in early 2017 with over 100 games, Xbox Game Pass has expanded to include over 250 Xbox One titles and 108 PC titles available for unlimited downloadable play as long as you maintain a subscription. All upcoming first-party Microsoft Studios games will be available on Game Pass the day they're released, and Ultimate members will receive the upcoming Gears 5 four days before release. Ultimate subscribers also receive free "Games with Gold" downloads each month as part of the included Xbox Live Gold membership.

We're not sure how long Microsoft is going to keep this introductory offer going. So if you're interested, don't wait.