NOTE 10—LITIGATION, COMMITMENTS, AND CONTINGENCIES

Fannie Mae DUS Related Commitments—Commitments for the origination and subsequent sale and delivery of loans to Fannie Mae represent those mortgage loan transactions where the borrower has locked an interest rate and scheduled closing and the Company has entered into a mandatory delivery commitment to sell the loan to Fannie Mae. As discussed in NOTE 9, the Company accounts for these commitments as derivatives recorded at fair value.

The Company is generally required to share the risk of any losses associated with loans sold under the Fannie Mae DUS program. The Company is required to secure these obligations by assigning restricted cash balances and securities to Fannie Mae. The amount of collateral required by Fannie Mae is a formulaic calculation at the loan level and considers the balance of the loan, the risk level of the loan, the age of the loan, and the level of risk-sharing. Fannie Mae requires restricted liquidity for Tier 2 loans of 75 basis points, which is funded over a 48-month period that begins upon delivery of the loan to Fannie Mae. Restricted liquidity held in the form of money market funds holding U.S. Treasuries is discounted 5% for purposes of calculating compliance with the restricted liquidity requirements. As of December 31, 2017, the Company held the majority of its restricted liquidity in money market funds holding U.S. Treasuries. Additionally, substantially all of the loans for which the Company has risk sharing are Tier 2 loans.

The Company is in compliance with the December 31, 2017 collateral requirements as outlined above. As of December 31, 2017, reserve requirements for the December 31, 2017 DUS loan portfolio will require the Company to fund $67.2 million in additional restricted liquidity over the next 48 months, assuming no further principal paydowns, prepayments, or defaults within the at risk portfolio. Fannie Mae periodically reassesses the DUS Capital Standards and may make changes to these standards in the future. The Company generates sufficient cash flow from its operations to meet these capital standards and does not expect any future changes to have a material impact on its future operations; however, any future changes to collateral requirements may adversely impact the Company’s available cash.

Fannie Mae has established benchmark standards for capital adequacy, and reserves the right to terminate the Company's servicing authority for all or some of the portfolio if at any time it determines that the Company's financial condition is not adequate to support its obligations under the DUS agreement. The Company is required to maintain acceptable net worth as defined in the agreement, and the Company satisfied the requirements as of December 31, 2017. The net worth requirement is derived primarily from unpaid balances on Fannie Mae loans and the level of risk sharing. At December 31, 2017, the net worth requirement was $155.8 million, and the Company's net worth was $725.9 million, as measured at our wholly owned operating subsidiary, Walker & Dunlop, LLC. As of December 31, 2017, the Company was required to maintain at least $30.7 million of liquid assets to meet operational liquidity requirements for Fannie Mae, Freddie Mac, HUD, and Ginnie Mae. As of December 31, 2017, the Company had operational liquidity of $238.6 million, as measured at our wholly owned operating subsidiary, Walker & Dunlop, LLC.

Litigation—In the ordinary course of business, the Company may be party to various claims and litigation, none of which the Company believes is material. The Company cannot predict the outcome of any pending litigation and may be subject to consequences that could include fines, penalties, and other costs, and the Company’s reputation and business may be impacted. The Company believes that any liability that could be imposed on the Company in connection with the disposition of any pending lawsuits would not have a material adverse effect on its business, results of operations, liquidity, or financial condition.

Lease Commitments—In the normal course of business, the Company enters into lease arrangements for all of its office space. All such lease arrangements are accounted for as operating leases. Rent expense related to these lease agreements is recognized on the straight-line basis over the term of the lease. Rent expense was $7.1 million, $6.4 million, and $5.9 million for the years ended December 31, 2017, 2016, and 2015, respectively.

Minimum cash basis operating lease commitments follow (in thousands):


Year Ending December 31,
2018	$	6,054
2019		5,860
2020		5,436
2021		4,904
2022		4,498
Thereafter		3,267
Total	$	30,019