39-year property · Straight line, mid-month
Includes: Alarm, sprinkler, camera and access-control systems in a commercial building.
| Line 12 · Section 179 expense | $0.00 |
|---|---|
| Line 14 · Special (bonus) depreciation | $0.00 |
| Line 19 · MACRS, 39-year property | $117.70 |
| Tax year | Rate | Depreciation | Accumulated | Basis left |
|---|---|---|---|---|
| 2026 | 0.535% | $117.70 | $117.70 | $21,882.30 |
| 2027 | 2.564% | $564.08 | $681.78 | $21,318.22 |
| 2028 | 2.564% | $564.08 | $1,245.86 | $20,754.14 |
| 2029 | 2.564% | $564.08 | $1,809.94 | $20,190.06 |
| 2030 | 2.564% | $564.08 | $2,374.02 | $19,625.98 |
| 2031 | 2.564% | $564.08 | $2,938.10 | $19,061.90 |
| 2032 | 2.564% | $564.08 | $3,502.18 | $18,497.82 |
| 2033 | 2.564% | $564.08 | $4,066.26 | $17,933.74 |
| 2034 | 2.564% | $564.08 | $4,630.34 | $17,369.66 |
| 2035 | 2.564% | $564.08 | $5,194.42 | $16,805.58 |
| 2036 | 2.564% | $564.08 | $5,758.50 | $16,241.50 |
| 2037 | 2.564% | $564.08 | $6,322.58 | $15,677.42 |
| 2038 | 2.564% | $564.08 | $6,886.66 | $15,113.34 |
| 2039 | 2.564% | $564.08 | $7,450.74 | $14,549.26 |
| 2040 | 2.564% | $564.08 | $8,014.82 | $13,985.18 |
| 2041 | 2.564% | $564.08 | $8,578.90 | $13,421.10 |
| 2042 | 2.564% | $564.08 | $9,142.98 | $12,857.02 |
| 2043 | 2.564% | $564.08 | $9,707.06 | $12,292.94 |
| 2044 | 2.564% | $564.08 | $10,271.14 | $11,728.86 |
| 2045 | 2.564% | $564.08 | $10,835.22 | $11,164.78 |
| 2046 | 2.564% | $564.08 | $11,399.30 | $10,600.70 |
| 2047 | 2.564% | $564.08 | $11,963.38 | $10,036.62 |
| 2048 | 2.564% | $564.08 | $12,527.46 | $9,472.54 |
| 2049 | 2.564% | $564.08 | $13,091.54 | $8,908.46 |
| 2050 | 2.564% | $564.08 | $13,655.62 | $8,344.38 |
| 2051 | 2.564% | $564.08 | $14,219.70 | $7,780.30 |
| 2052 | 2.564% | $564.08 | $14,783.78 | $7,216.22 |
| 2053 | 2.564% | $564.08 | $15,347.86 | $6,652.14 |
| 2054 | 2.564% | $564.08 | $15,911.94 | $6,088.06 |
| 2055 | 2.564% | $564.08 | $16,476.02 | $5,523.98 |
| 2056 | 2.564% | $564.08 | $17,040.10 | $4,959.90 |
| 2057 | 2.564% | $564.08 | $17,604.18 | $4,395.82 |
| 2058 | 2.564% | $564.08 | $18,168.26 | $3,831.74 |
| 2059 | 2.564% | $564.08 | $18,732.34 | $3,267.66 |
| 2060 | 2.564% | $564.08 | $19,296.42 | $2,703.58 |
| 2061 | 2.564% | $564.08 | $19,860.50 | $2,139.50 |
| 2062 | 2.564% | $564.08 | $20,424.58 | $1,575.42 |
| 2063 | 2.564% | $564.08 | $20,988.66 | $1,011.34 |
| 2064 | 2.564% | $564.08 | $21,552.74 | $447.26 |
| 2065 | 2.033% | $447.26 | $22,000.00 | $0.00 |
Basis = cost × business use · bonus = (basis − §179) × bonus rate · each year = (basis − §179 − bonus) × table rate
IRS Pub 946 tables · §179 and bonus per the One Big Beautiful Bill Act · car limits per §280F and the IRS yearly revenue procedure.
Placed in service March 2026, 100% business use, no section 179 or bonus.
| Tax year | Depreciation |
|---|---|
| 2026 | $447 |
| 2027 | $564 |
| 2028 | $564 |
| 2029 | $564 |
| 2030 | $564 |
| 2031 | $564 |
| 2032 | $564 |
| 2033 | $564 |
| 2034 | $564 |
| 2035 | $564 |
| 2036 | $564 |
| 2037 | $564 |
| 2038 | $564 |
| 2039 | $564 |
| 2040 | $564 |
| 2041 | $564 |
| 2042 | $564 |
| 2043 | $564 |
| 2044 | $564 |
| 2045 | $564 |
| 2046 | $564 |
| 2047 | $564 |
| 2048 | $564 |
| 2049 | $564 |
| 2050 | $564 |
| 2051 | $564 |
| 2052 | $564 |
| 2053 | $564 |
| 2054 | $564 |
| 2055 | $564 |
| 2056 | $564 |
| 2057 | $564 |
| 2058 | $564 |
| 2059 | $564 |
| 2060 | $564 |
| 2061 | $564 |
| 2062 | $564 |
| 2063 | $564 |
| 2064 | $564 |
| 2065 | $118 |
Source: Pub 946 chapter 2, qualified section 179 real property: fire protection and alarm systems and security systems on nonresidential real property. IRS Publication 946.
Security and fire protection systems are 39-year property under MACRS (the General Depreciation System), depreciated with straight line, mid-month. Under the Alternative Depreciation System the period is 40 years. Source: Pub 946 chapter 2, qualified section 179 real property: fire protection and alarm systems and security systems on nonresidential real property.
Section 179 lets you deduct up to $2,560,000 in 2026 (reduced above $4,090,000 of purchases), as long as the business has the income; this applies on nonresidential (commercial) buildings. Bonus depreciation does not apply to buildings and their structural components.
With no section 179 or bonus, placed in service in March 2026: $447 in 2026, $564 in 2027, $564 in 2028, $564 in 2029, and so on. The calculator above works it out for your own cost, date and business use.