NOTES TO CONSOLIDATED FINANCIAL STATEMENTS OF AMERICAN AIRLINES, INC. $^{(e)}$  Includes limited partnerships that invest primarily in U.S. (94%) and European (6%) buyout opportunities of a range of privately held companies. The pension plan’s master trust does not have the right to redeem its limited partnership investment at its net asset value, but rather receives distributions as the underlying assets are liquidated. It is estimated that the underlying assets of these funds will be gradually liquidated over the next one to ten years. Additionally, the pension plan’s master trust has future funding commitments of approximately $1.0 billion over the next ten years. $^{(f)}$  Certain investments that are measured using net asset value per share (or its equivalent) as a practical expedient for fair value have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the notes to the consolidated financial statements. $^{(g)}$  Investment includes 45% in an emerging market 103-12 Investment Trust with investments in emerging country equity securities, 37% in a collective interest trust investing primarily in short-term securities, 12% in Canadian segregated balanced value, income growth and diversified pooled funds and 6% in a common/collective trust investing in securities of smaller companies located outside the U.S., including developing markets. For some trusts, requests for withdrawals must meet specific requirements with advance notice of redemption preferred. Changes in fair value measurements of Level 3 investments during the year ended December 31, 2019, were as follows (in millions): Private Market Partnerships Insurance Group Annuity Contracts Beginning balance at December 31, 2018 $ 7 $ 2 Purchases 3 — Ending balance at December 31, 2019 $ 10 $ 2 Changes in fair value measurements of Level 3 investments during the year ended December 31, 2018, were as follows (in millions): The fair value of American’s retiree medical and other postretirement benefits plans assets by asset category, were as follows (in millions): Private Market Partnerships Insurance Group Annuity Contracts Beginning balance at December 31, 2017 $ 14 $ 2 Actual loss on plan assets: Relating to assets still held at the reporting date (2 ) — Purchases 1 — Sales (6 ) — Ending balance at December 31, 2018 $ 7 $ 2 Fair Value Measurements as of December 31, 2019 Asset Category Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Money market fund $ 4 $ — $ — $ 4 Mutual funds – AAL Class — 200 — 200 Total $ 4 $ 200 $ — $ 204 148