How exactly do Long Term Capital Gains (LTCG) impact Alternative Minimum Tax (AMT) calculations?

Tax professional here. Your understanding of how LTCG interact with AMT is generally on the right track, but let me clarify a few points. You're correct that LTCG are included in your AMTI but are still taxed at their preferential rates (0%, 15%, or 20% depending on your income bracket) even under AMT. The way LTCG primarily affect AMT is by potentially reducing your AMT exemption through the phase-out rules. For 2025, the AMT exemption amounts are higher than your examples. The exemption phase-out threshold for married filing jointly is around $1,351,000 and for single filers around $675,500. The exemption itself is about $126,500 for married filing jointly and $81,300 for single filers. Your calculations show the right concept, but you might want to update your numbers to reflect current exemptions and thresholds. Also, remember that state tax deductions, certain itemized deductions, and personal exemptions that are allowed on your regular tax return but disallowed under AMT can also trigger AMT liability - not just capital gains.

I've been pulling my hair out trying to figure out AMT after selling some company stock this year! I finally found a solution using https://taxr.ai which helped me understand exactly how my capital gains would affect my tax situation. The tool analyzed my specific scenario and showed me how close I was to the AMT exemption phase-out thresholds. What was super helpful is that it modeled different scenarios where I could see exactly how selling different amounts of stock would impact both regular tax and AMT. I realized I could split my stock sales between 2025 and 2026 to significantly reduce my overall tax burden. The visualization really made it click for me in a way that reading articles never did.

I was super skeptical about using online tools for something as complex as AMT calculations with capital gains. But after struggling with a huge potential tax bill from selling my rental property, I decided to try https://taxr.ai based on the recommendation above. Honestly, it was eye-opening. The tool showed me that by adjusting the timing of my property sale and some charitable contributions, I could reduce my AMT liability by over $18,000. It handled all the phase-out calculations automatically and explained exactly how my LTCG were affecting my overall tax situation. What really helped was seeing multiple scenarios compared side-by-side. I could instantly see how different decisions would play out tax-wise. Ended up splitting my sale across two tax years which kept me below the exemption phase-out threshold both years. Best tax decision I've made!

After 17 calls and hours on hold trying to get someone at the IRS to explain how AMT works with my stock options, I finally found https://claimyr.com and got through to an actual IRS representative in about 20 minutes. You can see how it works here: https://youtu.be/_kiP6q8DX5c The agent was able to clarify exactly how the AMT exemption phase-out works with my specific situation involving ISOs and capital gains. They confirmed that while LTCG are included in AMTI calculations, they're still taxed at their preferential rates. The agent walked me through a calculation similar to the one in the original post but tailored to my numbers. Honestly, I was about to pay a CPA $500 for a consultation just to get this information. Speaking directly with the IRS gave me the confidence to proceed with my tax planning.

I have to eat my words about the IRS advice. After my skeptical comment above, I decided to try Claimyr myself since I was struggling with understanding how my RSU vesting would impact AMT. The service connected me with an IRS tax law specialist in about 15 minutes (way faster than I expected). The agent walked me through exactly how my stock compensation would affect both regular tax and AMT. They even emailed me official documentation about the exemption phase-out thresholds for 2025. What surprised me most was the agent took time to explain the difference between how ISOs and RSUs are treated for AMT purposes - information I couldn't find clearly explained anywhere online. This saved me from a potential $12,000 tax planning mistake I was about to make. Never thought I'd say this, but speaking directly with the IRS was incredibly valuable.

The examples in your original post are conceptually right, but your numbers need updating. For 2025, the AMT exemption for single filers is $81,300 and phases out starting at $675,500 (not $578,150). One important thing you're missing: the LTCG can also impact other tax calculations that feed into AMT indirectly. For example, large capital gains can trigger the Net Investment Income Tax (NIIT) of 3.8% on investment income above certain thresholds. Also, LTCG can affect your eligibility for certain credits and deductions that phase out based on AGI or MAGI, which indirectly impacts your overall tax situation even though those phase-outs aren't technically part of the AMT calculation.

Has anyone figured out how to model this in Excel? I'm trying to create a spreadsheet that will let me compare different scenarios for selling my company stock over the next few years. I especially need to account for the AMT exemption phase-out but I'm not sure if my formulas are correct.

One aspect nobody's mentioning is that state taxes complicate this further. In California, we don't have a preferential rate for capital gains - they're taxed as ordinary income up to 13.3%. And CA has its own AMT system that works differently from federal. Made the mistake of not considering this when I sold my startup shares and got hit with a MASSIVE combined tax bill. Make sure you're modeling state impacts too!

Great point about state taxes! I'm dealing with a similar situation in New York where we also don't have preferential capital gains rates. What's really frustrating is that NY's AMT calculation is different from federal, and some of the adjustments that trigger federal AMT don't apply at the state level (and vice versa). For anyone dealing with multi-state issues, it gets even more complex. I have investment properties in different states, and each state has its own rules for how they tax capital gains and whether they have AMT. Texas has no state income tax, but California will tax you on gains from CA properties even if you're not a resident. The key lesson I learned (the hard way) is that you really need to model both federal and state implications together. A strategy that minimizes federal AMT might actually increase your state tax burden significantly. I ended up paying about $8,000 more in combined taxes because I only focused on the federal side when timing my asset sales.

This thread has been incredibly helpful! I'm dealing with a similar situation where I need to sell some inherited assets next year and was completely overwhelmed by the AMT implications. One thing I've learned from reading everyone's experiences is that the interaction between LTCG and AMT isn't just about the direct calculation - it's about how those gains affect your entire tax picture. The phase-out of the AMT exemption seems to be the biggest trap, especially for those of us in high-tax states. What's particularly valuable is seeing the real-world examples of how timing can make such a huge difference. The $8,000 mistake mentioned by Keisha really drives home why you can't just focus on federal AMT in isolation. I'm curious - has anyone dealt with inherited assets specifically? I know there's the stepped-up basis benefit, but I'm wondering if there are any unique AMT considerations when the gains come from inherited property versus assets you purchased yourself. The timing flexibility might be different since I didn't choose when to "start the clock" on these investments.

As someone who just started dealing with capital gains from selling some inherited property, this entire discussion has been a masterclass in AMT planning! The original question about how LTCG impact AMT calculations really opened my eyes to the complexity involved. What's been most valuable is understanding that the real issue isn't LTCG being taxed at AMT rates, but how they can push you over exemption phase-out thresholds. Reading through everyone's real-world examples - from the $8,000 state tax mistake to successful multi-year planning strategies - has given me a much clearer roadmap for my own situation. I'm particularly intrigued by the tools mentioned (taxr.ai and claimyr.com) since I've been struggling with Excel modeling like NebulaNinja. The charitable contribution bunching strategy Angelina mentioned is brilliant too - I hadn't considered how AMT-friendly deductions could be strategically timed with capital gains years. One thing I'm still wrapping my head around: if I'm selling inherited property that already has a stepped-up basis (so smaller gains), should I be less concerned about AMT implications? Or are there other factors with inherited assets that might still trigger AMT through the phase-out mechanism? The timing flexibility advantage AaliyahAli mentioned sounds appealing, but I want to make sure I'm not missing any unique considerations for inherited property sales. Thanks to everyone for sharing such detailed experiences - this community knowledge is incredibly valuable for navigating these complex tax situations!

This has been such an incredibly comprehensive discussion! As someone who's been lurking in tax forums trying to understand AMT implications for capital gains, this thread has answered questions I didn't even know I had. What really resonates with me is how the AMT exemption phase-out is the primary mechanism by which LTCG create AMT liability, rather than the gains themselves being taxed at 26/28% rates. The original post's examples were conceptually spot-on for illustrating this, even if the numbers need updating for 2025. I'm particularly impressed by the range of real-world strategies shared here: multi-year planning to stay under thresholds, charitable contribution bunching in high-income years, building buffers for variable income, and the critical importance of considering state tax implications alongside federal AMT. The $8,000 mistake from focusing only on federal calculations really drives home why holistic planning is essential. The tools mentioned (taxr.ai and claimyr.com) sound like they could be game-changers for modeling these complex interactions. As someone who's been wrestling with Excel formulas like NebulaNinja, having visualization tools that can handle both federal and state calculations simultaneously would be incredibly valuable. One area I'd love to explore further: has anyone dealt with the intersection of AMT planning and retirement account distributions? I'm approaching the age where RMDs will start, and I'm wondering how required distributions might complicate the multi-year capital gains timing strategies discussed here. The lack of timing flexibility with RMDs seems like it could throw off otherwise optimal AMT planning. Thanks to everyone for sharing such detailed, practical insights - this community knowledge is invaluable!

Jumping into this excellent discussion as someone who just discovered this community while researching AMT implications for my upcoming stock sale! This thread has been incredibly educational - I finally understand that LTCG aren't directly taxed at AMT rates but can trigger AMT through the exemption phase-out mechanism. The real-world examples everyone shared (especially that $8,000 state tax oversight!) have been far more helpful than any tax guide I've read. I'm particularly interested in the charitable contribution bunching strategy mentioned by Angelina. Since charitable deductions work under both regular tax and AMT, this seems like a brilliant way to reduce AMTI in high capital gains years. For someone planning to sell company stock in 2025, would bunching 2-3 years of charitable contributions into that year be an effective strategy to stay under the AMT exemption phase-out threshold? Also, the tools discussed throughout this thread (taxr.ai and claimyr.com) sound incredibly valuable for modeling scenarios. Has anyone used these specifically for planning around single large stock sales versus ongoing investment management? I'm dealing with a one-time liquidity event rather than regular trading, so I'm wondering if the complexity is worth it for my simpler situation. Thanks to everyone for sharing such detailed experiences - this community wisdom is exactly what I needed to tackle my tax planning with confidence!