I figured out my issue. I wasn’t using the correct credentials. I had a personal AWS account as my default credentials and needed to add my work profile to my credentials.
EDIT
If you have multiple aws profiles, you can mention the profile name at the docker login as below (assuming you have done aws configure --profile someprofile at earlier day),
aws ecr get-login-password --region us-east-1 --profile someprofile | docker login ....