The election is a real financial tradeoff, not a formality -- and the answer depends far more on your income in each year than most summaries suggest. Three worked examples below, all pinned to this calculator's own arithmetic, on the same $200,000 remaining unamortized balance.
$200,000 remaining balance, $500,000 of taxable income in both 2025 and 2026, a flat 21% rate both years, 6% annual discount rate.
| Line | 1-year path | 2-year path |
|---|---|---|
| 2025 deduction claimed | $200,000 | $100,000 |
| 2026 deduction claimed | $0 | $100,000 |
| 2025 cash savings | $42,000.00 | $21,000.00 |
| 2026 cash savings | $0.00 | $21,000.00 |
| Nominal total | $42,000.00 | $42,000.00 |
| Present value at 6%/year | $42,000.00 | $40,811.32 |
Same $42,000 nominal total either way -- the 1-year path only wins because that money arrives entirely in 2025 instead of split across two years. Present-value edge: $1,188.68 (2.83%) in the 1-year path's favor, from time value of money alone.
Same $200,000 balance and the same 21% rate both years, but 2025 taxable income before this deduction is only $20,000 -- a near-breakeven year -- while 2026 is back to $500,000.
| Line | 1-year path | 2-year path |
|---|---|---|
| 2025 deduction claimed / usable | $200,000 / $20,000 | $100,000 / $20,000 |
| 2025 excess (creates/increases an NOL) | $180,000 | $80,000 |
| 2025 cash savings | $4,200.00 | $4,200.00 |
| 2026 deduction claimed / usable | $0 / $0 | $100,000 / $100,000 |
| 2026 cash savings | $0.00 | $21,000.00 |
| Nominal total | $4,200.00 | $25,200.00 |
| Present value at 6%/year | $4,200.00 | $24,011.32 |
The 1-year path can only use $20,000 of its $200,000 deduction against 2025's thin income -- the other $180,000 does not vanish, but it becomes an NOL question this calculator does not model, instead of a cash saving today. The 2-year path wastes less into that same NOL gap in 2025 (only $80,000 excess against its smaller $100,000 claim) and puts its full second half to work against 2026's healthy income. Present-value gap: $19,811.32 -- nearly five times the 1-year path's total -- in the 2-year path's favor.
Same $200,000 balance, same $500,000 of income both years as example 1 -- but the business expects its marginal rate to rise from 21% in 2025 to 30% in 2026.
| Line | 1-year path | 2-year path |
|---|---|---|
| Present value at 6%/year | $42,000.00 | $49,301.89 |
Nothing about the income or the balance changed from example 1 -- only the expected 2026 rate did. That alone is enough to flip the present-value edge from +$1,188.68 for the 1-year path to +$7,301.89 for the 2-year path, because each dollar deducted in 2026 is now worth more per dollar than one deducted in 2025.
The Section 174A catch-up calculator runs this same present-value comparison on your own remaining balance, income, rates, and discount rate, and flags whenever a deduction would exceed a year's taxable income. Nothing you type leaves your browser.
A little, in the 1-year path's favor. On a $200,000 balance at a flat 21% rate both years and $500,000 of income each year, the 1-year path's $42,000 in savings arrives entirely in 2025, while the 2-year path's identical $42,000 nominal total splits $21,000/$21,000 across 2025 and 2026. Discounted at 6%/year, getting money sooner is worth about $1,188.68 more today -- a real but modest edge from time value of money alone.
This is where the two paths can diverge sharply. On the same $200,000 balance, if 2025 taxable income before this deduction is only $20,000, the 1-year path can only use $20,000 of the $200,000 deduction that year -- the remaining $180,000 does not vanish, but it creates or increases a net operating loss instead of an immediate cash saving, worth just $4,200 up front. The 2-year path claims $100,000 in 2025 (also capped at the $20,000 usable that year, so it wastes less into NOL territory on that half) and the other $100,000 in 2026 against a healthy $500,000 of income, capturing a full $21,000 there. Total nominal savings: $4,200 for the 1-year path versus $25,200 for the 2-year path -- a present-value gap of about $19,811.32 in the 2-year path's favor.
An expected rate increase independently favors the 2-year path, because the half deducted in 2026 is then worth more per dollar. On the same $200,000 balance at $500,000 of income both years, moving the 2026 rate from 21% to 30% flips the present-value edge from the 1-year path (+$1,188.68) to the 2-year path (+$7,301.89) -- a rate change alone is enough to change which election is better, even though nothing about the income or the balance changed.