Newmark shares risk of loss for loans originated under the Fannie Mae DUS and Freddie TAH programs and could incur losses in the event of defaults under or foreclosure of these loans. Under the guarantee, Newmark’s maximum contingent liability to the extent of actual losses incurred is approximately 33% of the outstanding principal balance on Fannie Mae DUS or Freddie TAH loans. Risk sharing percentages are established on a loan-by-loan basis when originated, with most loans at 33% and “modified” loans at lower percentages. Under certain circumstances, risk sharing percentages can be revised subsequent to origination or Newmark could be required to repurchase the loan. In the event of a loss resulting from a catastrophic event that is not required to be covered by borrowers’ insurance policies, Newmark can recover the loss under its mortgage impairment insurance policy. Any potential recovery is subject to the policy’s deductibles and limits.

At September 30, 2019, the credit risk loans being serviced by Newmark on behalf of Fannie Mae and Freddie Mac had outstanding principal balances of $19.9 billion with a maximum potential loss of $5.7 billion, of which $9.8 million is covered by the Credit Enhancement Agreement (See Note 12 — “Credit Enhancement Receivable, Contingent Liability and Credit Enhancement Deposit”).

At December 31, 2018, the credit risk loans being serviced by Newmark on behalf of Fannie Mae and Freddie Mac had outstanding principal balances of $20.6 billion with a maximum potential loss of $5.8 billion, of which $76.2 million is covered by the Credit Enhancement Agreement (See Note 12 — “Credit Enhancement Receivable, Contingent Liability and Credit Enhancement Deposit”).

Changes in the estimated liability under the guarantee liability were as follows (in thousands):

Financial guarantee liability
Balance, January 1, 2018	$	(54	)
Reversal of provision		22
Balance, December 31, 2018	$	(32	)
Increase to provision		(13	)
Balance, September 30, 2019	$	(45	)

In order to monitor and mitigate potential losses, Newmark uses an internally developed loan rating scorecard for determining which loans meet Newmark’s criteria to be placed on a watch list. Newmark also calculates default probabilities based on internal ratings and expected losses on a loan-by-loan basis. This methodology uses a number of factors, including, but not limited to, debt service coverage ratios, collateral valuation, the condition of the underlying assets, borrower strength and market conditions (See Note 12—"Credit Enhancement Receivable, Contingent Liability and Credit Enhancement Deposit” for further explanation of credit protection provided by DB Cayman). The provisions for risk sharing are included in “Operating, administrative and other” on the accompanying unaudited condensed consolidated statements of operations as follows (in thousands):

	Three Months Ended September 30,						Nine Months Ended September 30,
	2019			2018			2019		2018
Increase (decrease) to financial guarantee liability	$	(28	)	$	4		$	13	$	(3	)
Decrease (increase) to credit enhancement asset ⁽¹⁾	—			—			—			10
Increase (decrease) to contingent liability	—				(1	)	—		—
Total	$	(28	)	$	3		$	13	$	7