ACCRUED EXPENSES

The following table sets forth the Company’s accrued expenses (in thousands):



	March 31, 2016		December 31, 2015
Payroll-related expenses	$	23,500	$	37,419
Product returns	56,044		48,950
Accrued shelf stock	9,995		6,619
Government rebates ⁽¹⁾	99,606		91,717
Legal and professional fees	8,965		5,929
Income taxes payable	2,558		830
Physician detailing sales force fees	327		1,132
Interest payable	3,500		500
Other	8,617		11,615
Total accrued expenses	$	213,112	$	204,711

(1) Includes estimated $42.9 million and $40.6 million as of March 31, 2016 and December 31, 2015, respectively, of liabilities for Daraprim® chargebacks and rebates resulting from utilization by Medicaid, Medicare and other federal, state and local governmental programs, health plans and other health care providers for product sold under the Company’s labeler code, which amounts are subject to reimbursement by Turing in accordance with the terms of the Company's purchase agreement with Turing. The Company made payments of $5.1 million on Turing's behalf during the first quarter of 2016. See "Note 4. Summary of Significant Accounting Policies - Concentration of Credit Risk" for additional information related to the Turing receivable.

Product Returns

The Company maintains a return policy to allow customers to return product within specified guidelines. The Company estimates a provision for product returns as a percentage of gross sales based upon historical experience for sales made through its Impax Generics and Impax Specialty Pharma sales channels. Sales of product under the Private Label, Rx Partner and OTC Partner alliance, collaboration and supply agreements are not subject to returns.

A roll-forward of the return reserve activity for the three months ended March 31, 2016 and the year ended December 31, 2015 is as follows (in thousands):



Returns Reserve	March 31, 2016			December 31, 2015
Beginning balance	$	48,950		$	27,174
Acquired balances	—			11,364
Provision related to sales recorded in the period	13,421			43,967
Credits issued during the period	(6,327		)	(33,555		)
Ending balance	$	56,044		$	48,950