Final answer:
The liberalization clause is a policy provision that broadens coverage without requiring additional premium.
Step-by-step explanation:
The policy provision that automatically broadens coverage without requiring additional premium is the liberalization clause.
This clause allows the insurance company to enhance or relax the terms of the policy to the benefit of the insured, without charging extra premium. For example, if a new treatment or therapy becomes available, the liberalization clause would ensure that the policy covers it even if it wasn't originally included.