Also, in the first quarter of 2020, we entered into a strategic partnership with WCAS to accelerate the expansion of our primary care model. The WCAS partnership opened 20 payor-agnostic, senior-focused primary care centers during 2020, and is expected to open an additional 30 over the next 2 years.
Our effective tax rate during 2020 was 28.0% compared to the effective tax rate of 22.0% in 2019. This change primarily was due to the reinstatement of the non-deductible health insurance industry fee in 2020. See Note 12 to the consolidated financial statements included in Item 8. - Financial Statements and Supplementary Data for a complete reconciliation of the federal statutory rate to the effective tax rate.
•Group and Specialty segment loss was $143 million in 2020, a decrease of $171 million, or 610.7%, from $28 million of segment earnings in 2019 primarily due to the net negative impact of a higher operating cost ratio, partially offset by a slightly lower benefit ratio as more fully described below.
Our ongoing capital expenditures primarily relate to our information technology initiatives, support of services in our provider services operations including medical and administrative facility improvements necessary for activities such as the provision of care to members, claims processing, billing and collections, wellness solutions, care coordination, regulatory compliance and customer service. Total capital expenditures, excluding acquisitions, were $964 million in 2020, $736 million in 2019, and $612 million in 2018. The increase in capital expenditures year over year was primarily due to information technology expenditures supporting our integrated care delivery model.
We repurchased common shares for $1.82 billion, $1.07 billion and $1.09 billion in 2020, 2019 and 2018 under share repurchase plans authorized by the Board of Directors and in connection with employee stock plans.
The completion and claims per member per month trend factors are the most significant factors impacting the IBNR estimate. The portion of IBNR estimated using completion factors for claims incurred prior to the most recent two months is generally less variable than the portion of IBNR estimated using trend factors. The following table illustrates the sensitivity of these factors assuming moderately adverse experience and the estimated potential impact on our operating results caused by reasonably likely changes in these factors based on December 31, 2020 data:
We receive monthly premiums from the federal government and various states according to government specified payment rates and various contractual terms. We bill and collect premiums from employer groups and members in our Medicare and other individual products monthly. Changes in premium revenues resulting from the periodic changes in risk-adjustment scores derived from medical diagnoses for our membership are estimated by projecting the ultimate annual premium and recognized ratably during the year with adjustments each period to reflect changes in the ultimate premium.
The risks inherent in assessing the impairment of an investment include the risk that market factors may differ from our expectations, facts and circumstances factored into our assessment may change with the passage of time, or we may decide to subsequently sell the investment. The determination of whether a decline in the value of an
Also in the first quarter of 2020, our Partners in Primary Care wholly-owned subsidiary entered into a strategic partnership with Welsh, Carson, Anderson & Stowe, or WCAS, to accelerate the expansion of our primary care model. The WCAS partnership opened 20 payor-agnostic, senior-focused primary care centers during 2020, and is expected to open an additional 30 over the next 2 years. Partners in Primary Care committed to the acquisition of a non-controlling interest in the approximately $600 million entity. In addition, the agreement includes a series of put
The summarized balance sheets and statements of income at December 31, 2020 and 2019 of Kindred at Home were as follows:
Approximately 96% of our debt securities were investment-grade quality, with a weighted average credit rating of AA- by S&P at December 31, 2020. Most of the debt securities that were below investment-grade were rated BB, the higher end of the below investment-grade rating scale. Tax-exempt municipal securities were diversified among general obligation bonds of states and local municipalities in the United States as well as special revenue bonds issued by municipalities to finance specific public works projects such as utilities, water and sewer, transportation, or education. Our general obligation bonds are diversified across the United States with no individual state exceeding 1% of our total debt securities. Our investment policy limits investments in a single issuer and requires diversification among various asset types.
Due to the short-term nature, carrying value approximates fair value for commercial paper borrowings. The commercial paper borrowings were $600 million and $300 million at December 31, 2020 and December 31, 2019, respectively.
The provision for income taxes was different from the amount computed using the federal statutory rate for the years ended December 31, 2020, 2019 and 2018 due to the following:
Our senior notes, which are unsecured, may be redeemed at our option at any time at 100% of the principal amount plus accrued interest and a specified make-whole amount. The 8.15% senior notes are subject to an interest rate adjustment if the debt ratings assigned to the notes are downgraded (or subsequently upgraded). In addition, our senior notes contain a change of control provision that may require us to purchase the notes under certain circumstances.
Under our commercial paper program we may issue short-term, unsecured commercial paper notes privately placed on a discount basis through certain broker dealers at any time not to exceed $2 billion. Amounts available under the program may be borrowed, repaid and re-borrowed from time to time. The net proceeds of issuances have been and are expected to be used for general corporate purposes. The maximum principal amount outstanding at any one time during the year ended December 31, 2020 was $600 million, with $600 million outstanding at December 31, 2020 compared to $300 million outstanding at December 31, 2019. The outstanding commercial paper at December 31, 2020 had a weighted average annual interest rate of 0.34%.
Approximately 33% of the nonvested restricted stock at December 31, 2020 included performance-based conditions.
On December 22, 2020, we entered into separate accelerated stock repurchase agreements, ("the December 2020 ASR Agreements"), with Citibank, N.A., or Citi, and JPMorgan Chase Bank, or JPM, to repurchase $1.75 billion of our common stock as part of the $3 billion repurchase program authorized by the Board of Directors on July 30, 2019. On December 23, 2020, in accordance with the December 2020 ASR Agreements, we made a payment of $1.75 billion ($875 million to Citi and $875 million to JPM) and received an initial delivery of 3.8 million shares of our common stock (1.9 million shares each from Citi and JPM). We recorded the payments to Citi and JPM as a reduction to stockholders’ equity, consisting of an $1.5 billion increase in treasury stock, which reflects the value of the initial 3.8 million shares received upon initial settlement, and a $262.5 million decrease in
Excluding shares acquired in connection with employee stock plans, share repurchases were as follows during the years ended December 31, 2020, 2019 and 2018.
CMS is phasing-in the process of calculating risk scores using diagnoses data from the Risk Adjustment Processing System, or RAPS, to diagnoses data from the Encounter Data System, or EDS. The RAPS process requires MA plans to apply a filter logic based on CMS guidelines and only submit diagnoses that satisfy those guidelines. For submissions through EDS, CMS requires MA plans to submit all the encounter data and CMS will apply the risk adjustment filtering logic to determine the risk scores. For 2020, 50% of the risk score was calculated from claims data submitted through EDS. CMS increased that percentage to 75% for 2021 and will complete the phased-in transition from RAPS to EDS by using only EDS data to calculate risk scores in 2022. The phase-in from RAPS to EDS could result in different risk scores from each dataset as a result of plan processing issues, CMS processing issues, or filtering logic differences between RAPS and EDS, and could have a material adverse effect on our results of operations, financial position, or cash flows.