When it comes to equities and equity funds, the definition of long term capital gains is a holding period of more than 1 year. In this tax the benefit of indexation will not be available even if you hold shares for longer periods of time. For example, even if you sell shares after 15 years holding, the tax will be imposed at a flat rate of 10% on the capital gains. The only benefit that you will get is a basic exemption of Rs.1 lakh and any capital gains above the level of Rs.1 lakh will be taxable at 10%. When it comes to your financial plan and the goals that you have tagged to your equity mutual fund SIP, this LTCG tax will impact you in two ways; it impacts your corpus and also your regular contribution. There is one more thing to remember here. For example, if you have other losses on similar assets then you can either write off these losses or you can carry forward for 8 years. That reduces the effective impact on your long term capital gains.