In 2020, we adopted ASU 2016-13, which resulted in a new recognition and measurement of credit losses on most financial assets. See Note 2 for additional information. We established an allowance for credit losses of $192 million as of January 1, 2020, for reinsurance-related assets for the risk of credit losses inherent in reinsurance transactions. We estimated an allowance for credit losses for all reinsurance recoverables and related reinsurance deposit assets held by our subsidiaries. As such, we performed a quantitative analysis using a probability of loss approach to estimate expected credit losses for reinsurance recoverables, inclusive of similar assets recognized using the deposit method of accounting. The ACL is a general allowance for credit losses for pools of receivables with similar risk characteristics segmented by credit risk ratings and receivables assessed on an individual basis that do not share similar risk characteristics where we anticipate a credit loss over the life of reinsurance-related assets.

Our model uses relevant internal or external historical loss information adjusted for current conditions and reasonable and supportable forecasts of future events and conditions in developing our loss estimate. We utilized historical credit rating data to form an estimation of probability of default of counterparties by means of a transition matrix that provides the rates of credit migration for credit ratings transitioning to impairment. We updated reinsurer credit ratings during the quarter to incorporate the most up-to-date information on the current state of the financial stability of our reinsurers. To simulate changes in economic conditions, we used positive, base and adverse scenarios that include varying levels of loss given default assumptions to reflect the impact of changes in severity of losses. We applied probability weights to the positive, base and adverse scenarios. For periods beyond our reasonable and supportable forecasts, we used implicit mean reversion over the remaining life of the recoverable. Additionally, we considered factors that impact our exposure at default that are driven by actuarial expectations around term and mortality assumptions rather than being directly driven by market or economic environment.

Our model estimates the expected credit losses over the life of the reinsurance asset. Credit loss estimates are segmented based on counterparty credit risk. Our modeling process utilizes counterparty credit ratings, collateral types and amounts, and term and run-off assumptions. For reinsurance recoverables that do not share similar risk characteristics, we assessed on an individual basis to determine a specific allowance for credit losses.

We estimated expected credit losses over the contractual term of the recoverable, which is the period during which we are exposed to the credit risk. Reinsurance recoverables may not have explicit contractual lives, but are tied to the underlying insurance products; as a result, we estimated the contractual life by utilizing actuarial estimates of the timing of payouts related to those underlying products.

Reinsurance treaties often require the reinsurer to collateralize the recoverable with funds in a trust account for the benefit of the ceding insurance entity that can reduce the expected credit losses on a given treaty. As such, we review reinsurance collateral by individual treaty to sensitize risk of loss based on level of collateralization. This review is driven by the assumption that non-collateralized reinsurance recoverables would have materially higher losses in time of default. Therefore, reinsurance recoverables are pooled as either fully-collateralized or non-collateralized.

Reinsurance recoverables are presented net of the allowance for credit losses on our Consolidated Balance Sheets. Changes in the ACL are reported in realized gain (loss) on our Consolidated Statements of Comprehensive Income (Loss). Reinsurance recoverables deemed uncollectible are charged against the ACL, and subsequent recoveries, if any, are credited to the ACL, limited to the aggregate of amounts previously charged-off and expected to be charged-off.

Some portions of our annuity business have been reinsured on a Modco basis with other companies. In a Modco agreement, we as the ceding company retain the reserves, as well as the assets backing those reserves, and the reinsurer shares proportionally in all financial terms of the reinsured policies based on their respective percentage of the risk. Effective October 1, 2018, we entered into one such Modco agreement with Athene Holding Ltd. (“Athene”) to reinsure fixed and fixed indexed annuity products, which resulted in a deposit asset of $6.1 billion and $6.6 billion as of June 30, 2020, and December 31, 2019, respectively, within other assets on our Consolidated Balance Sheets. We held assets in support of reserves associated with the transaction in a Modco investment portfolio, which consisted of the following (in millions):


	As of		As of
	June 30,		December 31,
	2020		2019
Fixed maturity AFS securities	$	1,710		$	2,308
Trading securities		3,580			3,534
Equity securities		15			14
Commercial mortgage loans		777			698
Derivative investments		95			130
Other investments		105			94
Cash and invested cash		76			62
Accrued investment income		51			57
Total	$	6,409		$	6,897