The difference between myuhcmedicare.com and activate.uhc.com comes down to their purpose and when you use them:
activate.uhc.com
Used only for activating your UHC card (UCard)
First step after receiving your card
Helps verify your identity and link your card to your account
Limited functionality (activation only)
myuhcmedicare.com
Used for managing your Medicare account after activation
Let's you view benefits, check claims, track spending, and find providers
Ongoing access to your health plan details
Requires login (HealthSafe ID)
In simple terms:
activate.uhc.com = Activate your card (one-time use)
myuhcmedicare.com = Manage your account (regular use)
You typically activate your card first, then use myuhcmedicare.com to access and manage your healthcare benefits going forward.