| Operating revenue | 7,515a | 7,462a | 8,596a |
| Operating expenses | — | — | — |
| Fuel for electric generation | -624a | -561a | -905a |
| Purchased and interchange power | -1,333a | -1,375a | -1,928a |
| Purchased power - related parties | -71a | -75a | -76a |
| Cost of gas sold | -640a | -902a | -1,256a |
| Maintenance and other operating expenses | -1,638a | -1,687a | -1,669a |
| Depreciation and amortization | -1,240a | -1,180a | -1,126a |
| General taxes | -482a | -447a | -412a |
| Total operating expenses | -6,028a | -6,227a | -7,372a |
| Operating income | 1,487a | 1,235a | 1,224a |
| Other income (expense) | — | — | — |
| Non-operating retirement benefits, net | 169a | 180a | 205a |
| Other income | 207a | 195a | 19a |
| Other expense | -32a | -13a | -27a |
| Total other income | 344a | 362a | 197a |
| Interest charges | — | — | — |
| Interest on long-term debt | -700a | -616a | -509a |
| Interest expense - related parties | -12a | -12a | -12a |
| Other interest expense | -14a | -18a | |
| Allowance for borrowed funds used during construction | -18a | -3a | -2a |
| Total interest charges | -708a | -643a | -519a |
| Income before income taxes | 1,123a | 954a | 902a |
| Income tax expense | -176a | -147a | -93a |
| Income from continuing operations | 947a | 807a | 809a |
| Income from discontinued operations, net of tax | | 1a | 4a |
| Net income | 947a | 808a | 813a |
| Loss attributable to noncontrolling interests | -56a | -79a | -24a |
| Net income attributable to CMS Energy | 1,003a | 887a | 837a |
| Preferred stock dividends | 10a | 10a | 10a |
| Net income available to common stockholders | 993a | 877a | 827a |