Our products generally include warranties of 90 days to five years for product defects. Warranty returns are accrued at the time revenue is recognized based on an estimate of the cost to repair or replace the defective products. We engage in extensive product quality programs and processes, including actively monitoring and evaluating the quality of our component suppliers. Products continue to become more complex in both size and functionality as many of our product offerings migrate from line card applications to total systems. The increasing complexity of products will cause warranty incidences, when they arise, to be more costly. Estimates regarding future warranty obligations may change due to product failure rates, material usage and other rework costs incurred in correcting a product failure. In addition, from time to time, specific warranty accruals may be recorded if unforeseen problems arise. Should actual experience relative to these factors be worse than estimated, additional warranty expense will be incurred. Alternatively, if actual costs incurred are less than estimated, a portion of the warranty reserves will be reversed in future periods. The liability for warranty obligations totaled $7.2 million and $8.4 million as of September 30, 2020 and December 31, 2019, respectively, and are included in accrued expenses and other liabilities in the accompanying Condensed Consolidated Balance Sheets.

A reconciliation of warranty expense and related write-off activity for the three and nine months ended September 30, 2020 and 2019 is as follows:

	Three Months Ended						Nine Months Ended
	September 30,						September 30,
(In thousands)	2020			2019			2020			2019
Balance at beginning of period	$	7,294		$	8,972		$	8,394		$	8,623
Plus: Amounts charged to cost and expenses		632			816			970			3,796
Less: Deductions		(734	)		(1,131	)		(2,172	)		(3,762	)
Balance at end of period	$	7,192		$	8,657		$	7,192		$	8,657