Debt Fund Taxation Post-2023: Why Indexation Benefits Were Removed and What Changed

For nearly three decades, debt mutual funds carried a tax advantage that made them structurally superior to bank fixed deposits for holding periods beyond three years: indexation. The Finance Act, 2023 removed that advantage in a single stroke, and the change is still catching investors off guard who bought debt funds out of old habit rather than checking current rules.

What Indexation Actually Did, and Why It Mattered

Indexation allowed an investor to inflate their original purchase cost using the Cost Inflation Index (CII) before computing long-term capital gains — reducing the taxable gain by the amount inflation had already eroded, rather than taxing the investor on a gain that was partly illusory. For a debt fund held three or more years, this routinely cut the effective tax rate well below the flat 20% rate that applied at the time, and meaningfully below the slab rate a fixed deposit's interest income faced. This was the structural reason debt funds outcompeted FDs for long-term debt allocation.

The Finance Act, 2023 Change — What It Actually Did

Effective for units acquired on or after 1 April 2023, the Finance Act, 2023 inserted Section 50AA, deeming all capital gains from a "specified mutual fund" to be short-term, regardless of the actual holding period, and taxed entirely at the investor's applicable income tax slab rate. Indexation was withdrawn simultaneously. Under the original definition (applicable for FY 2023-24 and FY 2024-25), a "specified mutual fund" was any fund investing 35% or less of its total proceeds in equity shares of domestic companies — a definition broad enough to sweep in nearly every debt fund, gold fund, and international fund on the market.

Why the Change Was Made

The government's stated rationale centred on tax-neutrality between debt mutual funds and bank fixed deposits — a long-standing industry complaint from banks, who argued that debt funds enjoyed an unfair structural tax edge purely through indexation, despite offering economically comparable fixed-income exposure. Removing indexation and taxing debt fund gains identically to FD interest — at slab rate, with no long-term concession — was framed as levelling this playing field, though it materially reduced the after-tax appeal of debt funds for investors in higher tax brackets.

The FY 2025-26 Narrowing — A Meaningful Course Correction

The Finance (No. 2) Act, 2024 revisited the definition, effective FY 2025-26 (AY 2026-27) onwards. Under the revised rule, "specified mutual fund" now means a fund investing more than 65% of its total proceeds in debt and money market instruments, or a fund-of-funds investing 65% or more of its proceeds into such a debt-oriented fund. This is a genuinely narrower test than the original 35%-equity threshold, and its practical effect is significant: gold ETFs, gold fund-of-funds, and most international funds — which were caught under the old definition purely because they hold little domestic equity — are no longer treated as specified mutual funds from FY 2025-26. Our companion pieces on gold fund and fund-of-funds taxation cover what applies to those categories instead.

What Remains Unchanged — Pure Debt Funds Still Lose Indexation Entirely

For a genuine debt-oriented fund — one holding more than 65% in debt and money market instruments — nothing has improved. Units acquired on or after 1 April 2023 remain taxed at slab rate on the entire gain, with no long-term holding benefit and no indexation, exactly as under the original 2023 rule. For an investor in the 30% bracket, this makes a long-held debt fund's post-tax return materially worse than it would have been under the pre-2023 regime, and directly comparable to a fixed deposit's after-tax return rather than superior to it.

The Grandfathering That Still Matters

Units of debt-oriented mutual funds acquired before 1 April 2023 continue to enjoy the grandfathering protection preserved by the Finance Act, 2023. Unlike units acquired on or after that date, these older investments are not governed by Section 50AA.

Accordingly, once the applicable long-term holding period is satisfied, capital gains continue to be taxed at 20% with indexation, preserving the tax benefit that historically made debt funds attractive for long-term investors.

For transfers taking place under the current law, the long-term holding period for these grandfathered non-equity mutual fund units is 24 months, reflecting the subsequent rationalisation of holding periods introduced by the Finance (No. 2) Act, 2024.

This grandfathering remains an important planning consideration. Investors who accumulated debt funds through SIPs before and after 1 April 2023 may have units within the same folio falling under completely different tax regimes, making lot-wise tracking essential before redemption.

Market-Linked Debentures and the Extension to Unlisted Bonds

Section 50AA was also extended, effective for transfers on or after 23 July 2024, to cover unlisted bonds and unlisted debentures directly — gains from their transfer, redemption, or maturity are now deemed short-term and taxed at slab rate, mirroring the debt fund treatment. Listed bonds and debentures are unaffected by this extension and retain the standard 12-month long-term threshold at 12.5%.

What This Means for Portfolio Construction Today

The practical consequence for FY 2026-27 is that debt mutual funds no longer carry an automatic tax edge over fixed deposits for high-bracket investors holding for the long term — the decision between the two should now rest on liquidity, interest-rate positioning, and credit quality rather than an assumed tax advantage that no longer exists for units bought after April 2023. Investors with a genuine multi-year debt allocation should reassess whether a debt fund still makes sense purely on tax grounds, separately from its investment merits.

Getting the Lot-Level Detail Right

Because grandfathering depends entirely on the exact acquisition date of each unit, and SIP/STP instalments in a debt fund can straddle the 1 April 2023 cutoff within a single folio, getting this right requires lot-level tracking, not a single blended assumption. We help investors reconcile their debt fund holdings against the correct regime for each acquisition lot before filing.

This article reflects the law as understood at the time of writing for FY 2026-27 (AY 2027-28) and is for general informational purposes only. It does not constitute tax advice specific to any individual's circumstances — please consult a qualified Chartered Accountant before making a filing or investment decision.