PFICs (foreign mutual funds, UCITS ETFs) trigger Section 1291 tax for US investors — gains allocated across the holding period, taxed at top ordinary rates, plus compounded interest charges. This guide covers Form 8621, the QEF and mark-to-market elections, the $25k/$50k de minimis filing exception, and how to escape the trap.
How Section 121 lets U.S. homeowners exclude up to $250,000 ($500,000 for joint filers) of capital gains on a primary home sale — covering the 24-month ownership and use tests, the two-year frequency rule, partial exclusions, depreciation recapture, and the nonqualified-use allocation.
OBBBA permanently restored the EBITDA-based ATI calculation for Section 163(j) starting in 2025, expanding deductible business interest for capital-intensive companies. A guide to the 30% cap, the ~$31M small business exemption, the 35% syndicate trap, EBIE allocations from partnerships, S-corp differences, and Form 8990 reporting.
Section 25D's 30% residential clean energy credit ends December 31, 2025 under the OBBBA. How to file the final-year claim on Form 5695, carry unused credit forward indefinitely, and use TPO leases or Section 48E to capture value in 2026.
Section 280E bars cannabis businesses from deducting ordinary expenses, pushing federal effective tax rates past 70%. A walkthrough of the math, the COGS lever under Section 471, key Tax Court rulings (CHAMP, Olive, Harborside), and what 2026 rescheduling could change.
Section 280F caps first-year depreciation on passenger autos at $20,300 in 2026, but SUVs and trucks rated above 6,000 lbs GVWR escape those limits and can combine a $32,000 Section 179 deduction with 100% bonus depreciation. A practical guide to the 2026 numbers, the heavy-vehicle and pickup carve-outs, the 50% business-use cliff, and the mileage-log standards an IRS auditor expects.
Section 831(b) microcaptive insurance lets small businesses retain underwriting profit on hard-to-insure risks, but the IRS's 2025 final regulations treat captives with loss ratios under 30% as listed transactions. Here is how to structure one that survives an audit.
How short-term rentals sit outside the Section 469 passive loss rules, what the seven-day average and material participation tests actually require, and how a six-figure W-2 earner can use cost segregation and 100% bonus depreciation to legally offset wage income.
A 2026 walkthrough of every small business tax obligation—federal income, self-employment, payroll, sales, and excise—with the full filing calendar, quarterly estimated tax safe harbors, OBBBA-era changes (permanent QBI, $1.21M Section 179, restored 100% bonus depreciation), and the recordkeeping habits that prevent penalties.
After OBBBA set the federal estate, gift, and GST exemption at $15 million per person in 2026, SLATs still freeze growth out of the taxable estate at a 40 percent rate. Coverage of dual-SLAT reciprocal trust risk, asset selection, valuation discounts, and the audit records families need to keep.