Case Study: Cost Segregation Audit and Defense Outcome

Investor Marco purchased a $3.2M strip mall (building basis $2.56M) and commissioned a cost segregation study ($12,000) that reclassified 34% of the building basis ($870,000) into shorter-lived categories. With 80% bonus depreciation (2023 acquisition), the study generated $696,000 in Year 1 bonus depreciation on reclassified components, plus standard depreciation on the remaining basis. Total Year 1 depreciation: $789,000 (versus $65,641 without cost segregation). Marco's return reported a $650,000 rental loss, which he deducted against his W-2 income via REPS qualification. The IRS selected the return for examination based on the large Schedule E loss relative to W-2 income.

The examiner challenged three components of the study. Challenge 1: $85,000 in electrical systems classified as 5-year property. The examiner argued these were building electrical (39-year). The engineering firm responded that these were dedicated circuits serving specific tenant equipment (HVAC units, specialized refrigeration), not general building electrical—supported by Whiteco Industries factors and IRS CCA 200913023. Challenge 2: $120,000 in decorative façade elements classified as 15-year land improvements. The examiner argued these were structural (39-year). The engineering firm provided photographs and specifications showing the elements were removable without structural damage—meeting the test for tangible personal property. Challenge 3: $45,000 in parking lot striping and signage classified as 15-year. The examiner initially accepted this classification, as it aligns with IRS published guidance. After six months of examination, the examiner proposed reclassifying only the $120,000 decorative façade elements to 39-year property, accepting the electrical and parking lot classifications.

Marco's tax attorney negotiated with the examiner and ultimately agreed to reclassify $60,000 of the $120,000 decorative elements (a compromise—$60,000 remained as 15-year, $60,000 moved to 39-year). Tax impact of the adjustment: approximately $10,400 in additional Year 1 tax plus $2,080 in accuracy-related penalty and $1,560 in interest. Total cost: $14,040. Compared to the original tax benefit of $189,360 ($789,000 depreciation × 24% rate), the adjustment represented a 7.4% reduction—the investor retained 92.6% of the original benefit. Audit defense costs: $6,500 in tax attorney fees plus the engineering firm's $2,000 audit participation fee. Total audit-related costs: $22,540. Net retained benefit: $189,360 − $14,040 − $8,500 = $166,820. The case demonstrates that well-documented cost segregation studies survive audit with minimal adjustment, and the cost of defense is a fraction of the benefit retained.