Paper 36 · 12 min read
On 1 April 2023, indexation on debt mutual funds was quietly buried. Overnight, the tax edge that made debt funds beat fixed deposits vanished — long-term gains on new debt-fund money are now taxed at your slab rate, no inflation adjustment, no 20% cap. This paper traces what died, what survived, and why arbitrage and equity-savings funds inherited the throne as the tax-smart "debt".
For two decades, the Indian debt mutual fund had a quiet superpower. Hold it for more than three years and long-term capital gains were taxed at 20% with indexation — your purchase cost was inflated by the government's cost-inflation index before the gain was computed. In a 6% inflation world, that indexation often erased most of the taxable gain. A debt fund earning 7% could hand the investor a post-tax return that a fixed deposit — taxed every year at full slab — simply could not touch.
The Finance Act 2023 ended it in a sentence. From 1 April 2023, gains on "specified mutual funds" — any fund holding 35% or less in Indian equity, which is every debt and most conservative-hybrid fund — are treated as short-term regardless of how long you hold them, and taxed at your slab rate. No indexation. No 20% ceiling. A 30%-bracket investor who once paid ~13% effective now pays 31.2% on the same gain.
One nuance the headlines missed: this applies to units bought on or after 1 April 2023. Older units retain grandfathered treatment — and Budget 2024 later handed those legacy units a flat 12.5% without indexation if held over 24 months and sold after 23 July 2024. So there are, briefly, three debt-fund tax regimes alive at once. But for every rupee invested today, only one matters: slab rate, full stop.
A 30%-slab investor, ₹10 lakh invested for five years at 7%, roughly ₹4 lakh of gain at exit. Here is what the tax authorities take from that gain under each vehicle — the pre-2023 debt fund, the post-2023 debt fund, the fixed deposit, and the arbitrage fund that now wears equity's tax clothes.
Read the chart twice. The debt fund didn't move a little — it jumped from the best-taxed option to sitting level with the fixed deposit it was built to beat. And the arbitrage fund, which most conservative investors had never opened, is now taxed more gently than the debt fund they've held for years.
The obituary is premature if you stop at the tax rate. A debt fund and a fixed deposit can be taxed at the identical slab rate and the debt fund still wins — because when the tax is paid is as important as the rate. Three survivors:
So the honest verdict on debt-fund-vs-FD is no longer "obviously the fund." It is: the fund still wins for the taxable, patient investor — through deferral, timing and SWP — but the margin is now a matter of engineering, not a free lunch handed over by indexation.
Here is the elegant accident of the 2023 change. Tax law defines an equity fund as one holding ≥65% in Indian equity. An arbitrage fund holds ≥65% equity too — but every equity position is fully hedged against an offsetting futures contract, so the market risk is cancelled out. The investor earns the low-risk spread between cash and futures (a debt-like 6–7%), while the fund is taxed as equity.
That means arbitrage funds get the entire equity tax package the debt fund just lost: 12.5% LTCG above the ₹1.25 lakh annual exemption after 12 months, and 20% STCG below it. For a 30%-slab investor parking money for a year or more, an arbitrage fund earning even less than a debt fund can deliver more in the hand — purely on tax.
Equity-savings funds extend the idea: ~65% equity (part hedged arbitrage, part naked equity) plus a debt sleeve. Slightly more risk, slightly more return, still equity taxation. They occupy the rung between arbitrage and conservative hybrid — for investors who can stomach a little volatility for a little more return, all under the friendlier tax code.
The 2023 change didn't kill debt funds — it re-sorted the parking lot. A cleaner map for taxable money by horizon and purpose:
| Need | Old default | Post-2023 tax-smart choice |
|---|---|---|
| Park < 1 year | Liquid / overnight debt fund | Arbitrage (if > slab benefit) or liquid |
| Park 1–3 years | Short-duration debt fund | Arbitrage / equity-savings fund |
| Emergency corpus | Liquid fund + sweep-FD | Arbitrage + small liquid buffer |
| Known date (3–5 yr goal) | Target-maturity / roll-down debt | Target-maturity debt (deferral still wins) |
| Guaranteed, capital-safe | Fixed deposit | Fixed deposit (unchanged) |
| Taxable investor, 30% slab, >1 yr | Debt fund (for indexation) | Arbitrage fund — 12.5% beats 31.2% |
Two cautions before the whole book migrates to arbitrage. First, arbitrage returns depend on market conditions — the cash-futures spread widens in bullish, volatile markets and compresses in calm ones; some months it under-earns a liquid fund. Second, arbitrage funds carry an exit load (typically 0.25% for 15–30 days), so they suit money you can leave alone for a month or more, not truly overnight cash.
Model the post-tax outcome across slabs and horizons in the Income Tax & Capital Gains calculators — then confirm the parking decision in FD vs MF.
Open the Tax Calculator →For the advisor, this is a conversation to have before the client's accountant does. Every rupee of new debt-fund money since April 2023 is taxed at slab — and a client parking ₹25 lakh for three years at 30% is handing over lakhs more than they need to, simply because nobody re-sorted the parking lot after the rule changed. The debt fund still has a role. It is just no longer the default, and it is no longer the tax hero. That crown now belongs to the fund most conservative investors have never opened.