4. Contract Assets and Liabilities

As of the beginning of the prior year period, or January 1, 2022, costs and estimated earnings in excess of billings on uncompleted contracts and billings in excess of costs and estimated earnings on uncompleted contracts were $51.4 million and $28.9 million, respectively. The contract liabilities recorded in “Accrued expenses” on the Condensed Consolidated Balance Sheets were $9.2 million, $4.5 million and $4.4 million as of September 30, 2023, December 31, 2022 and January 1, 2022, respectively. Approximately 75% of the Company's contract liabilities as of December 31, 2022 were recognized as revenue in the nine months ended September 30, 2023.