Which document identifies the subscriber's policy?

The document that best identifies the subscriber's policy is the subscriber number. This unique identifier is crucial for insurance claims processing, as it allows healthcare providers and insurers to quickly access the specific details of the policy holder's coverage. The subscriber number is a key component in managing patient information, processing claims, and identifying the subscriber's benefits, thereby streamlining communication between healthcare providers and insurance companies.

In contrast, other options like the claim form, receipt, and insurance card serve different purposes. The claim form provides details about services rendered and is utilized to request reimbursement from the insurer but does not serve as a direct identifier for the policy itself. A receipt is typically a proof of payment for services and also does not specify policy details. While an insurance card does contain essential information such as the subscriber's name and may feature the policy number, it is the subscriber number that explicitly connects to the specific insurance policy in process.