subject insurance operations to significant regulatory restrictions. As discussed in  Part I, Item 1, Business  and  Part I. Item 1A. Risk Factors , these laws and regulations require, among other things, that our insurance subsidiaries maintain minimum solvency requirements, which limit the amount of dividends that can be paid to the holding company. The regulations also require approval of our service agreements with the applicable regulatory authority in order to prevent insurance subsidiaries from moving large amounts of cash to the unregulated holding company. As we discussed in "2020 Highlights", Citizens had significant expenses in 2020 related to executive severance costs due to severance payable to our former Chief Executive Officer following the change in control. These expenses included payment of $8.8 million to a Rabbi Trust for the benefit of Mr. Kolander representing the severance payments due to him under his employment agreement and Chief Executive Officer Separation of Service and Consulting Agreement in connection with his resignation following a change in control. During the third quarter of 2020, Citizens sold approximately $5.7 million of fixed maturity securities held in our investment portfolio in order to fund a portion of the $8.8 million severance payment to the Rabbi Trust for the benefit of Mr. Kolander. The $8.8 million payment was paid to Mr. Kolander on February 8, 2021. We also incurred significant one-time expenses related to the build-out of our new headquarters in Austin, Texas and for the purchase of furniture and fixtures for the leased space. Additionally, as discussed in  Part I. Item 1. Business , on March 5, 2021, the Company paid $9.1 million to the Foundation to hold in escrow in order to purchase, upon obtaining final regulatory approval, 100% of the outstanding Class B common stock. See  Contractual Obligations and Off-balance Sheet Arrangements  below for a discussion of real estate lease payments to be made under our new long-term contract for our headquarters in Austin, Texas. We have been closely monitoring the impact that the COVID-19 pandemic may have on our liquidity and capital resources. To the extent that we continue to experience decreases in sales or collections of renewal premiums, increases in surrenders, decreases in our investment income and/or increases in claim payments as a result of the COVID-19 pandemic, the liquidity of our insurance subsidiaries would be negatively impacted, inhibiting their ability to make dividends to the Company, and we may have to sell some of our investments to meet operational cash flow requirements. INSURANCE COMPANY SUBSIDIARY LIQUIDITY AND CAPITAL RESOURCES Table of Contents CITIZENS, INC. The liquidity requirements of our insurance operations are primarily met by premium revenues, investment income and investment maturities. Primary cash needs are for payments of policy benefits to policyholders, investment purchases, and operating expenses. Historically, we have not had to liquidate investments to provide cash flow for our insurance operations and we did not do so in 2020. We believe that we have adequate capital resources to support the liquidity requirements of our insurance operations if the cash flow from our insurance operations is insufficient to meet our cash needs. As discussed above, premium revenue was $175.3 million and $184.3 million in the years ended December 31, 2020 and 2019, respectively. See  Contractual Obligations and Off-balance Sheet Arrangements  below for a discussion of known and estimated cash needs related to payments of future policy benefits and policy claims. Cash flows from operating activities were $48.8 million, $72.2 million and $84.6 million for the years ended December 31, 2020, 2019 and 2018, respectively. We have traditionally also had significant cash flows from both scheduled and unscheduled investment security maturities, redemptions, and prepayments. These cash flows, for the most part, are reinvested in fixed income securities and to a lesser extent private equity funds or other alternative investments. However, during the third quarter of 2020, the Company used funds from matured securities to pay $6.0 million to the IRS for the tax compliance matter described in  Note 7. Commitments and Contingencies in the notes to our consolidated financial statements. As noted in  , our payment does not represent closure of the matter or IRS acceptance of the tax liability shown on the submitted withholding tax returns, and the IRS reserves the right to revise our total tax liability for the covered period. Net cash outflows from investing activities totaled $61.8 million and $69.3 million for the years ended December 31, 2020 and 2019, respectively. The investing activities fluctuate from period to period due to timing of securities activities such as calls and maturities and reinvestment of those funds. December 31, 2020 | 10-K 58