Amounts recorded in accumulated other comprehensive loss consist of: December 31, 2019 2018 (Amounts in thousands) Unrecognized net gain $ 1,512 $ 3,365 Unrecognized prior service cost (856) (940) Accumulated other comprehensive income, net of tax $ 656 $ 2,425 We made contributions to the postretirement medical plans to pay benefits of $2.9 million in 2019, $3.2 million in 2018 and $2.5 million in 2017. Because the postretirement medical plans are unfunded, we make contributions as the covered individuals’ claims are approved for payment. Accordingly, contributions during any period are directly correlated to the benefits paid. We sponsor several defined contribution plans covering substantially all U.S. and Canadian employees and certain other non-U.S. employees. Employees may contribute to these plans, and these contributions are matched in varying amounts by us, including opportunities for discretionary matching contributions by us. Defined contribution plan expense was $20.4 million in 2019, $18.7 million in 2018 and $17.7 million in 2017. We are a defendant in a substantial number of lawsuits that seek to recover damages for personal injury allegedly caused by exposure to asbestos-containing products manufactured and/or distributed by our heritage companies in the past. While the overall number of asbestos-related claims has generally declined in recent years, there can be no assurance that this trend will continue, or that the average cost per claim will not further increase. Asbestos-containing materials incorporated into any such products were encapsulated and used as internal components of process equipment, and we do not believe that any significant emission of asbestos fibers occurred during the use of this equipment. Our practice is to vigorously contest and resolve these claims, and we have been successful in resolving a majority of claims with little or no payment. Historically, a high percentage of resolved claims have been covered by applicable insurance or indemnities from other companies, and we believe that a substantial majority of existing claims should continue to be covered by insurance or indemnities, in whole or in part. Accordingly, we have recorded a liability for our estimate of the most likely settlement of asserted claims and a related receivable from insurers or other companies for our estimated recovery, to the extent we believe that the amounts of recovery are probable. While unfavorable rulings, judgments or settlement terms regarding these claims could have a material adverse impact on our business, financial condition, results of operations and cash flows, we currently believe the likelihood is remote. Additionally, we have claims pending against certain insurers that, if resolved more favorably than reflected in the recorded receivables, would result in discrete gains in the applicable quarter. We are currently unable to estimate the impact, if any, of unasserted asbestos-related claims, although we expect that future claims would also be subject to then existing indemnities and insurance coverage. We are currently involved as a potentially responsible party at five former public waste disposal sites in various stages of evaluation or remediation. The projected cost of remediation at these sites, as well as our alleged "fair share" allocation, will remain uncertain until all studies have been completed and the parties have either negotiated an amicable resolution or the matter has been judicially resolved. At each site, there are many other parties who have similarly been identified. Many of the other parties identified are financially strong and solvent companies that appear able to pay their share of the remediation costs. Based on our information about the waste disposal practices at these sites and the environmental regulatory process in general, we believe that it is likely that ultimate remediation liability costs for each site will be apportioned among all liable parties, including site owners and waste transporters, according to the volumes and/or toxicity of the wastes shown to have been disposed of at the sites. We believe that our financial exposure for existing disposal sites will not be materially in excess of accrued reserves. Defined Contribution Plans 14.LEGAL MATTERS AND CONTINGENCIES Asbestos-Related Claims Other 94