Underlying Agreement is a field on the BAA Cover Page. It identifies the primary commercial agreement - such as a Cloud Software Agreement or Professional Services Agreement - that the BAA is being signed alongside.

A BAA governs how protected health information (PHI) is handled, but it doesn't stand alone. It is almost always paired with a separate underlying agreement that describes the actual business relationship - what services are being provided, by whom, and for how long. The Underlying Agreement field tells both parties which agreement the BAA is attached to.

You have two options:

Common Paper agreement - If you already have (or are creating) a Common Paper agreement with this counterparty, select it here. Use the Select an agreement dropdown to choose the relevant agreement from your account.

Describe the agreement - If the underlying agreement lives outside of Common Paper, use this option to describe it in plain language. Include the agreement type, the date it was signed, and the parties involved. For example: Professional Services Agreement signed on January 10, 2026 between Acme Corp and DataLily AI.

NOTE: It is unusual to sign a BAA without any underlying commercial agreement to reference. If you don't have one in place yet, consider whether a Pilot Agreement, Design Partner Agreement, or Professional Services Agreement might be appropriate before sending the BAA.

Default: No default - you must select one of the two options before sending.