Final answer:
The PPO or Preferred Provider Organization plan allows patients to see specialists without a referral. This plan offers flexibility in choosing healthcare providers, in contrast to HMOs which require referrals.
Step-by-step explanation:
The insurance coverage plan that allows a patient to see a specialist without a referral is the Preferred Provider Organization (PPO). In contrast to a Health Maintenance Organization (HMO), which requires referrals to see specialists and focuses on preventative care, PPOs offer more flexibility in choosing healthcare providers. The fee-for-service model, where medical care providers are reimbursed according to the services they provide, differs from the PPO model, where providers typically offer services to the members at discounted rates.
While Exclusive Provider Organizations (EPOs) also offer a network of providers, they often require choosing providers within a more limited network. A Point of Service (POS) plan combines elements of both HMOs and PPOs but typically still requires referrals for specialists.