If you’re shopping for a new RV right now, or you manage a campground, something just shifted that you need to know about. On June 9, 2026, the RV Industry Association confirmed a model year 2028 effective date for mandatory Grounding Monitor Interrupters on all new 30-amp and 50-amp RVs. This isn’t a rumor or a proposal still working through committees. It’s done. And depending on which side of the pedestal you’re standing on, it changes things.

What a GMI Actually Does (and Why It Matters)

A Grounding Monitor Interrupter is basically a bouncer for your shore power connection. Before the GMI lets any campground electricity into your RV, it checks that the pedestal has a proper ground. If the ground isn’t there, or if it disappears while you’re plugged in, the GMI cuts power instantly. No electricity flows until the problem is fixed.

Simple concept. Big implications. A missing or failed ground at a pedestal isn’t just annoying. It’s a real shock and fire hazard. Faulty campground wiring has caused some genuinely bad incidents over the years, and the industry has known for decades that pedestals across the country range from perfectly maintained to genuinely dangerous. The GMI requirement is codified in Article 551 of both the 2023 and 2026 editions of the National Electrical Code. RVIA spent more than six years developing the standard before getting here.

Why This Got Delayed, and What That Tells You

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MilestoneOriginal DateActual/Revised DateStatus
Initial Development Start~2018~2018Completed
NEC Codification2023 & 2026 editions2023 & 2026 editionsCodified
Original Enforcement DateJanuary 1, 2026DelayedMissed
Revised Enforcement Date-January 1, 2027Revised
Model Year Effective Date-2028Current
Development Duration-6+ yearsComplete

The rule was originally supposed to take effect January 1, 2026. It didn’t, and the reason matters: there simply weren’t enough commercially certified GMI devices available for manufacturers to use. You can’t require something that doesn’t exist in sufficient supply. RVIA pushed the enforcement date to January 1, 2027, with the model year 2028 cutoff giving manufacturers time to actually source and install the hardware.

Some safety advocates were frustrated by the delay. But honestly, rushing a mandate before the supply chain could handle it would’ve created different chaos. The extra lead time also gives campground operators a window to get their pedestals in order, which is the part of this story that deserves way more attention than it’s getting.

The Campground Problem Is Real

Here’s what should worry every future GMI-equipped RV owner. When your new rig pulls into a campground with a bad ground on the pedestal, the GMI isn’t going to shrug and let power through anyway. It’ll do exactly what it’s designed to do: block the connection. You’ll be sitting there with no shore power, staring at a pedestal that looks fine from the outside, while your batteries drain and your refrigerator warms up.

RVIA is already urging campground operators to test ground continuity from each pedestal back to the main service panel. Some parks are expected to start advertising “GMI-compatible” pedestals as a selling point, as noted in RV Travel’s December 2025 coverage of the incoming rule. That’s a good sign. But let’s be honest: a lot of campgrounds, especially smaller private parks and older state park systems, are running infrastructure that hasn’t been seriously evaluated in years. The GMI requirement is going to expose that gap in a very direct way.

If you manage a campground, treat the next 18 months as a gift. You have time to audit your pedestals before a wave of new GMI-equipped rigs shows up and refuses to connect. The cost of fixing a bad ground now is way less than the cost of reputation damage when guests can’t get power.

What This Means If You’re Buying a New RV

If you’re shopping for a 2026 or 2027 model year rig right now, GMI is not required. Those rigs don’t have to have it, and most won’t. The mandate applies to model year 2028 and beyond. So if you buy something this summer or fall, you’re in the current system: no GMI, same shore power behavior you’ve always had.

That’s not necessarily a reason to rush your purchase. Camper Report’s June 9, 2026 coverage made clear that the rule is now settled, and manufacturers have the runway to implement it properly. When 2028 model year rigs start shipping, the GMI hardware should be mature, tested, and integrated cleanly. Early adoption of a new safety system isn’t always where you want to be.

One thing that won’t change: if you already own an RV, you’re not required to retrofit a GMI. The rule only applies to new rigs. You might eventually want one, and I suspect the aftermarket will respond with retrofit options once the standard matures. But nobody’s mandating it for existing owners.

What I’d Watch for Between Now and 2028

The next 18 months are going to be telling. Watch for campground rating systems and apps to start incorporating pedestal grounding status. Watch for GMI-compatible to become a marketing term that parks use to attract the coming wave of compliant rigs. And watch for the first wave of 2028 model year rigs to hit the road and surface any real-world friction between GMI systems and the actual condition of campground infrastructure across the country.

The underlying goal here is one that anyone who’s spent time in campgrounds should appreciate. Bad campground power is a real problem, and the industry has been working around it with surge protectors and EMS devices for years. A GMI baked into every new rig is a more permanent answer. It puts the compliance pressure where it belongs: on the infrastructure, not on individual owners buying aftermarket protection.

Six years of development, two editions of the National Electrical Code, a missed 2026 deadline, and now a firm 2028 line in the sand. This one’s actually happening. If you’re buying new or running a park, now is when to start paying attention.

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