• For contracts entered on or after January 1, 2007, advance waivers of liens were declared void.
• Contractual waivers remain valid for contractors and subcontractors for residential buildings where the total contract price with the owner is under $1,000,000 and by subcontractors for residential buildings regardless of contract value if the contractor has posted a payment bond guaranteeing payment for labor and materials.
• Actual notice of an advance waiver by the contractor must be given to the subcontractor before any labor or materials are furnished, or the contract or separate written notice of such waiver must be filed in the office of the prothonotary prior to the commencement of the work upon the ground or within 10 days after the execution of the principal contract or not less than 10 days prior to the contract with the claimant subcontractor. 49 P.S. §1402
• "Paid if Paid" is enforced if explicit.
• "Pay when Paid" suggests time for payment.
• Pay-when-paid clause in the subcontract or purchase order does not create a condition precedent to payment.

Retainage Provisions

Public

• The rate of retainage may not exceed 10 percent. After 50 percent of the work is complete, the rate of retainage may not exceed 5 percent. At that point, if progress is satisfactory, one-half of the retained funds shall be returned to the contractor. 39 PA. CONS. STAT. § 3921.
• For contracts with the Department of General Services, the maximum rate of retainage is 6 percent until half of the project is complete. Thereafter, retainage may not exceed 3 percent. 39 PA. CONS. STAT. § 3921.
• For contracts involving highway work, retainage is 5 percent until the project is 50
  percent complete. Thereafter, no retainage is withheld. The Secretary of Transportation may
  waive or reduce retainage, if otherwise assured the contract will be completed, and may make
  payments to further reduce retainage whenthe project is 95 percent complete. 36 PA. CONS.
  STAT. § 746.