The changes in the carrying amount of goodwill for the six months ended June 30, 2022 are as follows (in millions):

Balance, as of December 31, 2021
Goodwill	$	7,033
Accumulated impairment losses		(2,814	)
		4,219
Goodwill acquired as part of acquisitions during current year		5
Goodwill allocated to hospitals held for sale		—
Balance, as of June 30, 2022
Goodwill		7,038
Accumulated impairment losses		(2,814	)
	$	4,224

Goodwill is allocated to each identified reporting unit, which is defined as an operating segment or one level below the operating segment (referred to as a component of the entity). Management has determined that the Company’s operating segment meets the criteria to be classified as a reporting unit.

Goodwill is evaluated for impairment annually and when an event occurs or circumstances change that, more likely than not, reduce the fair value of the reporting unit below its carrying value. The Company performed its last annual goodwill impairment evaluation during the fourth quarter of 2021 using an October 31, 2021 measurement date, which indicated no impairment.

The Company estimates the fair value of the reporting unit using both a discounted cash flow model as well as a market multiple model. The cash flow forecasts are adjusted by an appropriate discount rate based on the Company’s estimate of a market participant’s weighted-average cost of capital. These models are both based on the Company’s best estimate of future revenues and operating costs and are reconciled to the Company’s consolidated market capitalization, with consideration of the amount a potential acquirer would be required to pay, in the form of a control premium, in order to gain sufficient ownership to set policies, direct operations and control management decisions.

The determination of fair value in the Company’s goodwill impairment analysis is based on an estimate of fair value for the reporting unit utilizing known and estimated inputs at the evaluation date. Some of those inputs include, but are not limited to, the most recent price of the Company’s common stock and fair value of long-term debt, recent financial results of the Company, estimates of future revenue and expense growth, estimated market multiples, expected capital expenditures, income tax rates, and costs of invested capital.

A detailed evaluation of potential impairment indicators was performed as of June 30, 2022, which specifically considered declines in the fair market value of the Company’s outstanding senior secured and unsecured notes and common stock during the six months ended June 30, 2022, as well as macroeconomic conditions and the Company’s recent financial results, including the effect of increased wage and contract labor expense. On the basis of available evidence, as of June 30, 2022, the Company concluded that the fair value of the reporting unit was not more likely than not reduced to an amount less than its carrying value.

Future estimates of fair value could be adversely affected if the actual outcome of one or more of the assumptions described above changes materially in the future, including a decline in the Company’s stock price and the fair value of its long-term debt, an increase in the volatility of the Company’s stock price and the fair value of its long-term debt, lower than expected volumes and/or net operating revenues, higher market interest rates or increased operating costs. Such changes impacting the calculation of fair value could result in a material impairment charge in the future.