how do I do a horizontal analysis on the 10-k income statement? And what the numbers mean.

Horizontal Analysis- this is where you will pick a line item on the Income Statement, and trend it over time. There are 2 simple calculations to do this. First is the Net Change or Difference = Current Year less Prior Year. For example: 2020 = 500, 2019 = 300. Net Change year over year = +200. The second calculation is % Change = (Current Year less Prior Year) / Prior Year. Using the example above, the formula would be (500 - 300) / 300 = +67% growth over the prior year. Vertical Analysis- this explains the makeup or % total of a specific line item, and how it trends over time. Let's use the example of Supply Cost as a % of Total Operating Costs. If we use the example of: Supply Cost in 2020 = 25, and Total Costs in 2020 = 100. 25/ 100 = 25% of Total. Say the Total Cost remained the same in 2019, but the Supply Cost = 35. So the Supply Cost in 2019 = 35% of Total Costs. Now, take the difference between both years and you could say: Supply Costs as a percentage of Total Costs reduced by 10% year over year. Net operating revenues Operating costs and expenses: Salaries and benefits COMMUNITY HEALTH SYSTEMS, INC. AND SUBSIDIARIES CONSOLIDATED STATEMENTS OF INCOME (LOSS) Supplies Other operating expenses Government and other legal settlements and related costs Electronic health records incentive reimbursement Lease cost and rent Pandemic relief funds Depreciation and amortization Impairment and (gain) loss on sale of businesses, net Total operating costs and expenses Income from operations Interest expense, net of interest income of $3 in both 2020 and 2019 and $7 in 2018 (Gain) loss from early extinguishment of debt Equity in earnings of unconsolidated affiliates Income (loss) before income taxes (Benefit from provision for income taxes Net income foss) Less: Netancome attributable to noncontrolling interests Net incre loss) attributable to Community Health Systems, Inc. stockholders Earnings (los) per share attributable to Community Health Systems, In common stockholders: Basi Diluted Weighte 1-average number of shares outstanding Basic Diluted See accompanying notes to the consolidated financial statements. 83 $ $ Year Ended December 31, 2020 2018 2019 (In millions, except share and per share data) 11,789 $ $ 13,210 5,411 1,963 2,957 327 (601) 558 48 10,663 1,126 1,031 (317) (10) 422 (185) 607 96 511 4.43 4.39 115,491,022 116,544,561 $ $ 5,947 2,151 3,303 93 (1) 321 608 138 12,560 650 1,041 54 (15) (430) 160 (590) 85 (675) (5.93) $ (5.93) 113,739,046 113,739,046 14,155 6,384 2,355 3,496 11 (4) 337 700 668 13,947 208 976 (31) (22) (715) (11) (704) 84 (788) (6.99) (6.99) 112,728,274 112,728.274