Credit Risk

Financial instruments that potentially subject the Company to concentrations of credit risk primarily consist of cash and cash equivalents placed with high credit quality financial institutions, accounts receivable due from customers and other receivables.

Management evaluates the collectability of accounts receivable based on a combination of factors. If management becomes aware of a customer's inability to meet its financial obligations after a sale has occurred, the Company records an allowance to reduce the net receivable to the amount that management reasonably believes to be collectable from the customer. If the financial conditions of MRV's customers were to deteriorate or if economic conditions worsen, additional allowances may be required in the future. Accounts receivable are charged off at the point they are considered uncollectible.

The following table summarizes the changes in the allowance for doubtful accounts during the three months ended March 31, 2017 (in thousands):



Balance at beginning of period	$	267
Reversed to expense	(60		)
Write-offs, net of amounts recovered	(29		)
Balance at end of period	$	178