Does a sump pump in a basement require GFCI protection?
Yes. If the sump pump plugs into a receptacle in a basement, that receptacle needs GFCI protection under the 2023 NEC. Section 210.8(A)(5) requires GFCI protection for all 125 volt through 250 volt receptacles supplied by single-phase branch circuits rated 150 volts or less to ground, 50 amperes or less, installed in basements of dwelling units. There is no carve-out for sump pumps, and the exception that used to let you feed a single receptacle serving a permanently installed appliance without GFCI was deleted several code cycles ago.
Why electricians still argue about this
The confusion comes from older code books. The 2011 and earlier editions applied basement GFCI rules only to unfinished portions of the basement, and there was an exception for a single receptacle supplying a permanently installed appliance identified for the use, plus another for a receptacle dedicated to a fire alarm or burglar alarm system. The 2014 edition dropped the appliance exception. The 2020 edition expanded the rule to the entire basement, finished and unfinished, and raised the voltage ceiling to 250 volts so 240 volt receptacles are included. By the 2023 edition, the only exception left in 210.8(A) is the listed fire alarm or burglar alarm system receptacle in 210.8(A)(5), and a sump pump is not a fire alarm.
What about a hardwired pump
Section 210.8(A) is written around receptacles, so a permanently connected sump pump with no cord and plug is not swept in by 210.8(A)(5). Check 422.5(A) before you assume you are clear, because that section lists the appliances that require GFCI regardless of how they are connected, and it covers things like drinking water coolers, vending machines, and sump pumps are not on that list in the 2023 edition. Some jurisdictions amend this. If you hardwire the pump specifically to dodge the GFCI rule, expect an inspector to ask why.
Nuisance tripping and how to handle it
Older shaded-pole and split-phase pump motors do leak current, and a marginal pump on a fresh GFCI will trip. That is not a reason to remove the protection. It is a reason to replace the pump. Megger the motor windings if you want proof before you spend a customer's money. A self-testing GFCI receptacle or a Class A GFCI breaker will both do the job. If the basement floods when the pump is offline, install a high-water alarm on a separate circuit so a trip does not go unnoticed, and label the receptacle so the homeowner knows where to reset it.
Field takeaway
Cord-and-plug sump pump in any dwelling basement gets GFCI protection, finished or unfinished, 120 volt or 240 volt. Put the protection where the homeowner can reach it, use a device with a visible trip indicator, and add a water alarm on a different circuit for anything protecting finished space.