15 Pa.C.S. § 8436: Partner's liability.

(a) General rule.--Except as provided in subsection (b) or section 8204 (relating to limitation on liability of partners), all partners are jointly and severally liable for all debts, obligations and other liabilities of the partnership unless otherwise agreed by the claimant or provided by law.

(b) Preexisting liabilities.--A person that becomes a partner is not personally liable for a debt, obligation or other liability of the partnership incurred before the person became a partner.