Both occupations earn self-employment income — farmers on Schedule F, self-employed commercial fishermen on Schedule C (fishing is not “farming” for the farm schedule) — and both owe self-employment tax on the net. What sets them apart from every other trade is two deliberate concessions Congress wrote for income that arrives in violent, weather- and catch-driven swings.
Income averaging. Under IRC §1301, “Averaging of farm income”, a farmer or fisherman can elect on Schedule J to spread the current year’s farm or fishing income back across the prior three years’ tax brackets. A boom year — a record harvest, a once-in-a-decade salmon run — that would otherwise spike into the top bracket is taxed as if it had been earned evenly over four years. This is one of the only genuine income-averaging provisions left in the code after the 1986 repeal of general averaging; in a bumper year it is worth real money, and it can be elected, revoked, or changed on an amended return once the numbers are known.
The estimated-tax break. If at least two-thirds of your gross income comes from farming or fishing, IRC §6654(i) frees you from the quarterly estimated-payment treadmill: make a single estimated payment by January 15, or skip estimates entirely if you file your return and pay the full balance by March 1. It is a cash-flow concession to operations that have nothing to pay with until the crop or the catch sells.
Beyond these, scattered relief tracks the specific risks of each trade. Farmers can defer income from livestock sold early because of drought or flood, defer crop-insurance and disaster proceeds ( IRC §451), and — unusually — still carry a net operating loss back two years under IRC §172 after the TCJA stripped the carryback from almost everyone else. Commercial fishermen have their own deferral vehicle: a Capital Construction Fund lets a vessel owner set aside pre-tax earnings to build, buy, or reconstruct a boat, in effect a retirement-style deferral aimed at the fleet rather than the fisherman.
The catch-share trap snares deckhands. Crew on a boat normally carrying fewer than ten hands are treated as self-employed under IRC §3121(b)(20) when they are paid a share of the catch rather than a wage — so the boat issues a Form 1099, no FICA is withheld, and the crew member owes self-employment tax on the share. A deckhand who assumed those settlement checks were take-home pay meets the 15.3% bill at filing.