OPERATING SEGMENTS | NOTE 14. OPERATING SEGMENTS Operating segments under GAAP are defined as components of an enterprise about which separate financial information is available that is evaluated regularly by the Chief Operating Decision Maker (CODM), or decision-making group, in deciding how to allocate resources and in assessing performance. Our CODM is the President and Chief Operating Officer. Our reportable operating segments consist of Engine, Distribution, Components, Power Systems and Electrified Power. This reporting structure is organized according to the products and markets each segment serves . The Engine segment produces engines (15 liters and smaller) and associated parts for sale to customers in on-highway and various off-highway markets. Our engines are used in trucks of all sizes, buses and recreational vehicles, as well as in various industrial applications, including construction, agriculture, power generation systems and other off-highway applications. The Distribution segment includes wholly-owned and partially-owned distributorships engaged in wholesaling engines, generator sets and service parts, as well as performing service and repair activities on our products and maintaining relationships with various OEMs throughout the world. The Components segment sells filtration products, aftertreatment systems, turbochargers, electronics, fuel systems and transmissions. The Power Systems segment is an integrated power provider, which designs, manufactures and sells engines (16 liters and larger) for industrial applications (including mining, oil and gas, marine and rail), standby and prime power generator sets, alternators and other power components. The Electrified Power segment designs, manufactures, sells and supports electrified power systems ranging from fully electric to hybrid solutions along with innovative components and subsystems to serve all our markets as they adopt electrification, meeting the needs of our OEM partners and end customers. We use EBITDA (defined as earnings before interest expense, income taxes, noncontrolling interests, depreciation and amortization) as the primary basis for the CODM to evaluate the performance of each of our reportable operating segments. Segment amounts exclude certain expenses not specifically identifiable to segments. The accounting policies of our operating segments are the same as those applied in our Condensed Consolidated Financial Statements. We prepared the financial results of our operating segments on a basis that is consistent with the manner in which we internally disaggregate financial information to assist in making internal operating decisions. We allocate certain common costs and expenses, primarily corporate functions, among segments differently than we would for stand-alone financial information prepared in accordance with GAAP. These include certain costs and expenses of shared services, such as information technology, human resources, legal, finance and supply chain management. We do not allocate changes in cash surrender value of corporate owned life insurance to individual segments. EBITDA may not be consistent with measures used by other companies. Summarized financial information regarding our reportable operating segments for the three months ended is shown in the table below: In millions Engine Distribution Components Power Systems Electrified Power Total Segments Intersegment Eliminations (1) Total Three months ended June 30, 2019 External sales $ 2,073 $ 2,015 $ 1,401 $ 724 $ 8 $ 6,221 $ — $ 6,221 Intersegment sales 630 13 445 479 — 1,567 (1,567 ) — Total sales 2,703 2,028 1,846 1,203 8 7,788 (1,567 ) 6,221 Research, development and engineering expenses 88 7 75 57 24 251 — 251 Equity, royalty and interest income from investees 62 12 11 11 — 96 — 96 Interest income 4 4 2 2 — 12 — 12 Segment EBITDA 416 172 297 173 (33 ) 1,025 33 1,058 Depreciation and amortization (2) 51 28 47 30 2 158 — 158 Three months ended July 1, 2018 External sales $ 2,050 $ 1,988 $ 1,402 $ 691 $ 1 $ 6,132 $ — $ 6,132 Intersegment sales 646 6 485 555 — 1,692 (1,692 ) — Total sales 2,696 1,994 1,887 1,246 1 7,824 (1,692 ) 6,132 Research, development and engineering expenses 76 5 62 60 16 219 — 219 Equity, royalty and interest income from investees 67 11 14 18 — 110 — 110 Interest income 3 3 2 2 — 10 — 10 Segment EBITDA 362 145 237 186 (21 ) 909 (12 ) 897 Depreciation and amortization (2) 47 27 47 32 1 154 — 154 ____________________________________ (1) Includes intersegment sales, intersegment profit in inventory eliminations and unallocated corporate expenses. There were no significant unallocated corporate expenses for the three months ended June 30, 2019 and July 1, 2018 . (2) Depreciation and amortization, as shown on a segment basis, excludes the amortization of debt discount and deferred costs included in the Condensed Consolidated Statements of Net Income as "Interest expense." A portion of depreciation expense is included in "Research, development and engineering expenses." Summarized financial information regarding our reportable operating segments for the six months ended is shown in the table below: In millions Engine Distribution Components Power Systems Electrified Power Total Segments Intersegment Eliminations (1) Total Six months ended June 30, 2019 External sales $ 4,057 $ 4,008 $ 2,802 $ 1,347 $ 11 $ 12,225 $ — $ 12,225 Intersegment sales 1,299 21 905 933 — 3,158 (3,158 ) — Total sales 5,356 4,029 3,707 2,280 11 15,383 (3,158 ) 12,225 Research, development and engineering expenses 166 14 150 113 45 488 — 488 Equity, royalty and interest income from investees 118 23 21 26 — 188 — 188 Interest income 8 8 4 4 — 24 — 24 Segment EBITDA 854 343 622 311 (62 ) 2,068 23 2,091 Depreciation and amortization (2) 101 57 93 59 4 314 — 314 Six months ended July 1, 2018 External sales $ 3,863 $ 3,835 $ 2,715 $ 1,286 $ 3 $ 11,702 $ — $ 11,702 Intersegment sales 1,279 12 925 1,034 — 3,250 (3,250 ) — Total sales 5,142 3,847 3,640 2,320 3 14,952 (3,250 ) 11,702 Research, development and engineering expenses 155 10 124 117 23 429 — 429 Equity, royalty and interest income from investees 134 24 30 37 — 225 — 225 Interest income 5 5 3 4 — 17 — 17 Segment EBITDA 648 268 464 328 (31 ) 1,677 (80 ) 1,597 Depreciation and amortization (2) 96 54 93 62 2 307 — 307 ____________________________________ (1) Includes intersegment sales, intersegment profit in inventory eliminations and unallocated corporate expenses. There were no significant unallocated corporate expenses for the six months ended June 30, 2019 and July 1, 2018 . (2) Depreciation and amortization, as shown on a segment basis, excludes the amortization of debt discount and deferred costs included in the Condensed Consolidated Statements of Net Income as "Interest expense." The amortization of debt discount and deferred costs was $1 million and $1 million for the six months ended June 30, 2019 and July 1, 2018 , respectively. A portion of depreciation expense is included in "Research, development and engineering expenses." A reconciliation of our segment information to the corresponding amounts in the Condensed Consolidated Statements of Net Income is shown in the table below: Three months ended Six months ended In millions June 30, July 1, June 30, July 1, Total EBITDA $ 1,058 $ 897 $ 2,091 $ 1,597 Less: Depreciation and amortization 158 154 314 307 Interest expense 29 28 61 52 Income before income taxes $ 871 $ 715 $ 1,716 $ 1,238 |