Yes, lien waivers can indeed be negotiated and modified in contracts. Common terms to consider include:
Specifying that waivers are conditional upon actual receipt and clearance of payments.
Clearly defining the scope of work covered by the waiver.
Including provisions for partial waivers if only a portion of the payment is made.
Specifying the timeframe within which waivers must be provided.
Establishing procedures for resolving disputes related to payments and waivers.