4. Accounts Receivable and Significant Concentrations

A significant portion of the Company’s revenue arrangements consist of firm fixed price contracts with agencies of the U.S. federal government and several large multinational publicly traded and private corporations. Accounts receivable consist of the following by customer type in the table below as of the periods presented:

As of December 31, 2023, the Company had accounts receivable, net of $8.2 million.

(1) Government contracts are generally firm fixed price not to exceed arrangements with a term of five (5) years, which consists of a base year and four (4) annual option year renewals. Government receivables are billed under a single consolidated monthly invoice and are billed approximately thirty (30) to sixty (60) days in arrears from the date of service and payment is generally due within thirty (30) days of the invoice date. Government accounts receivable payments could be delayed due to administrative processing delays by the government agency, government shutdown, and continuing budget resolutions that may delay availability of contract funding, and/or administrative only invoice correction requests by contracting officers that may delay payment processing by our government customer.

(2) Commercial contracts are generally fixed price arrangements with contract terms ranging from two (2) to three (3) years. Commercial accounts receivables are billed based on the underlying contract terms and conditions which generally have repayment terms that range from thirty (30) to ninety (90) days. Commercial receivables are stated at amounts due from customers net of an allowance for credit losses if deemed necessary.

(3) During the year ended December 31, 2025 and 2024, the Company did not recognize any material provisions or recoveries of existing provision for credit losses. The Company has not historically maintained an allowance for credit losses for its government customers as it has not experienced material or recurring bad debt charges and the nature and size of the contracts has not necessitated the Company’s establishment of such an allowance for credit losses.

Significant Concentrations

The following table presents revenue by customer for each of the periods presented:

(1) Sales to the U.S. federal government include sales from contracts for which we are the prime contractor, as well as those for which we are a subcontractor and the ultimate customer is the U.S. government.