Disclosed are various approaches for retrieving contacts from a plurality of federated services. In one example, an authentication notification is received from an identity manager. The authentication notification can include an identifier for a user account and a single sign-on token for the user account. A federated service to authenticate on behalf of the user account is identified. The single sign-on token is transmitted to the federated service for authentication. An authentication token and a refresh token are received from the federated service. The authentication token is determined to expire within a threshold time period. A determination is made that the refresh token has not expired. The refresh token is transmitted to the federated service for a replacement authentication token.