Answer: Please send an email to carefirstmedicareadvantage@carefirst.com for information about joining the Medicare Advantage HMO or PPO networks. CareFirst Advantage, Inc. offers eligible providers an opportunity to participate in the CareFirst Medicare Advantage HMO network, which is utilized for the CareFirst Advantage product, an Individual HMO product. CareFirst Advantage PPO, Inc. offers eligible providers an opportunity to participate in the CareFirst Medicare Advantage PPO network, which is utilized for the CareFirst BlueCross BlueShield Group Advantage product, a Group PPO product.