Here is an excerpt from an actual policy:
"The plan covering the patient as a dependent child of a person whose date of birth occurs earlier in the calendar year shall be primary over the plan covering the patient as a dependent of a person whose date of birth occurs later in the calendar year provided."
If the policy were written for a reader to understand, the passage might read:
"What happens if my spouse and I both have health coverage for our child?
"If your child is covered under more than one insurance policy, the policy of the adult whose birthday is earlier in the year pays the claim first. For example: Your birthday is in March; your spouse's birthday is in May. March comes earlier in the year than May, so your policy will pay for your child's claim first."
Much better. The rewrite, taken from a New York Times piece by a lawyer who works in a state health insurance department in Rhode Island, has shorter sentences, simpler vocabulary, and a clear example.
This health insurance commissioner's office frequently receives calls from citizens who do not understand why coverage is denied. When the state office follows up with insurers, the companies often don't understand their own policies. Clear writing would benefit everyone involved.