What does Block 20 ask for to be marked when lab tests are done by an entity other than the billing entity?

Block 20 of the CMS-1500 form is specifically designed to indicate whether lab tests were performed by an entity other than the one submitting the claim for payment. The correct response in this context is “Yes or No,” which allows the insurance company to clearly understand who performed the tests and whether the billing entity is separate from the testing entity. This information is critical for determining coverage and appropriately processing the claim.

When lab tests are performed by an external entity, answering "Yes" would indicate that the billing entity is not the same as the laboratory that conducted the tests, thus requiring the claims processor to consider any specific billing agreements or procedures that may apply. Conversely, answering "No" would indicate that the tests were conducted in-house by the billing entity.

The other choices, such as “Maybe,” “Not Applicable,” or true/false options, do not provide the clear, definitive response needed for accurate claims processing in the context of lab tests being performed by an external entity. These alternatives could lead to confusion and misinterpretation when the claim is evaluated, reinforcing the necessity of the straightforward "Yes or No" format.