The offer saves customers $47.94 from a separate Disney+ subscription, which costs $7.99 per month for unlimited access to Disney classics as wel as Marvel, Lucasfilm, Pixar and National Geographic content.
If you already have Music Unlimited or are a returning customer, you can get 3 months of Disney for free instead, a $23.97 saving.
It's worth noting that the Disney+ subscription will automatically renew after six months unless you cancel your Amazon Music Unlimited subscription within the promotional period.
If you don't want to carry on with either service after six months, you'll need to cancel both your Amazon Music Unlimited subscription and Disney+ subscription separately – canceling one won't automatically cancel the other.
Those outside the US and Canada might be able to access the deal too using a VPN. NordVPN and Surfshark are our top choices, but see our choices of the best VPN for streaming for additional recommendations.
Don't forget you can also get Disney+ for free with Hulu and ESPN+ for $12.99.
Amazon's offer arrives as retailers compete in Fourth of July sales – see the best deals and discounts you can get right now.