Depreciation and amortization expense was $28.7 million for the third quarter of 2018 compared to $25.1 million for the third quarter of 2017, an increase of $3.6 million that primarily related to the amortization of intangible assets from recent acquisitions.
Interest expense was $21.8 million for the third quarter of 2018 compared to $18.4 million for the third quarter of 2017, due primarily to a higher effective interest rate on borrowings between the two periods and slightly higher outstanding borrowings.
MEDNAX generated net income of $65.6 million for the 2018 third quarter, or $0.72 per diluted share based on a weighted average 91.4 million shares outstanding. This compares with net income of $65.9 million, or $0.71 per diluted share, for the 2017 third quarter, based on a weighted average 92.9 million shares outstanding. The decrease of 1.5 million in weighted average shares outstanding is primarily due to the impact of shares repurchased under the Company’s share repurchase programs.
The Company’s effective tax rate for the third quarter of 2018 was 27.5 percent, compared to 39.0 percent for the third quarter of 2017, related to the reduction in the corporate tax rate enacted under the Tax Cuts and Jobs Act of 2017.
For the third quarter of 2018, MEDNAX reported Adjusted EPS of $0.94, compared to $0.87 for the third quarter of 2017. Adjusted EPS is defined as diluted net income per common and common equivalent share excludingnon-cash amortization expense and stock-based compensation expense.
For the nine months ended September 30, 2018, MEDNAX generated revenue of $2.71 billion, up 6.6 percent from $2.55 billion for the prior-year period. EBITDA for the nine months ended September 30, 2018 was $432.2 million, compared to $433.3 million for the prior year. MEDNAX earned net income of $208.4 million, or $2.25 per share, through September 30, 2018, based on a weighted average 92.8 million shares outstanding, which compares to net income of $184.3 million, or $1.98 per share, based on a weighted average 93.0 million shares outstanding for the first nine months of 2017. For the nine months ended September 30, 2018, MEDNAX reported Adjusted EPS of $2.90, compared to $2.47 in the same period of 2017.
MEDNAX had cash and cash equivalents of $34.5 million at September 30, 2018, and net accounts receivable were $522.8 million.
During the third quarter of 2018, MEDNAX generated cash from operations of $140.7 million, compared to $199.9 million during the 2017 third quarter. Cash flow from operations for the 2017 third quarter was favorably impacted by the deferral of tax payments for companies impacted by the 2017 hurricanes. During the third quarter of 2018, MEDNAX used $250.0 million of cash to repurchase its common stock under its existing $500 million share repurchase authorization, via an accelerated share repurchase program.
At September 30, 2018, MEDNAX had total net debt outstanding of $2.0 billion, consisting of its borrowings under its revolving credit facility and senior notes. At September 30, 2018, the amount of additional borrowing capacity available under the Company’s revolving credit facility was approximately $735 million.