Is Amazon Quietly Forcing Sellers Off Hybrid FBA/FBM Setups?

Something unusual is reportedly happening inside Amazon’s Seller Performance division, and mid-market operators are starting to compare notes. Since approximately late March 2026, a growing number of sellers running hybrid FBA/FBM fulfillment setups — using Fulfilled by Merchant as a buffer against FBA stockouts — have allegedly been receiving Account Health warnings at disproportionate rates, even when their order defect rates sit well below Amazon’s published 1% threshold.

Sources close to the matter say the warnings are tied to a quiet change in how Amazon’s internal algorithms score “fulfillment consistency” for hybrid ASINs — a metric that, notably, does not appear in any published Seller Central documentation as of May 2026.

What Are Sellers Actually Receiving in Their Dashboards?

According to three separate seven-figure Amazon sellers who spoke with Ecommerce Times on condition of anonymity, the warnings reference “inconsistent delivery promise accuracy” on FBM-fulfilled orders that were activated during FBA inventory gaps. One seller, running approximately $4.2M in annual Amazon revenue across the home goods category, said their account health score dropped from 280 to 191 within a two-week window in April despite no change in operational performance.

“We’ve been running this hybrid model for four years. FBM was our safety valve during Q4 stockouts. Now suddenly Amazon is calling it a reliability signal problem. It feels like the goalposts moved and nobody told us.” — anonymous seven-figure seller, home goods category

Helium 10’s community Slack — which now reportedly counts over 34,000 active members — saw threads on this topic accumulate more than 400 replies in a single week in mid-May, with sellers from apparel, pet supplies, and sporting goods all reporting similar patterns. Jungle Scout’s seller forum has seen parallel activity, though neither company has issued a formal advisory as of publication.

Is This an Amazon Policy Shift or an Algorithm Glitch?

That’s the central dispute right now. Sources close to the matter say Amazon’s Selling Partner Services team has been inconsistent in its explanations when sellers escalate. Some account managers are apparently describing it as a “temporary scoring recalibration” tied to the broader rollout of Amazon’s fulfillment reliability index — an internal scoring layer that reportedly feeds into Buy Box eligibility weighting and is unconfirmed to be connected to the Rufus AI infrastructure updates from earlier this year.

Others are allegedly being told their FBM shipping carriers are the issue — specifically that non-Amazon-partnered carriers used for FBM backup fulfillment are being scored more harshly under updated estimated delivery date (EDD) accuracy standards that quietly took effect in February 2026.

Nate Ginsburg, founder of SellerPlex and a well-known figure in the Amazon aggregator-adjacent ecosystem, posted publicly on LinkedIn in early May suggesting the pattern looks less like a glitch and more like deliberate policy architecture.

“Amazon has a $140B logistics infrastructure it needs to fill. Every seller running hybrid fulfillment is a seller they haven’t fully captured. I don’t think these warnings are accidental.” — Nate Ginsburg, SellerPlex

Ginsburg’s post reportedly generated significant private DMs from aggregator operators, several of whom are allegedly reviewing their own hybrid setups ahead of Q3 inventory planning cycles.

Which Seller Categories Are Being Hit Hardest?

Based on seller reports aggregated across the Helium 10 community, the MXED Sellers Facebook group (reportedly 67,000 members), and direct sourcing by Ecommerce Times, the categories showing the highest concentration of warnings include:

• Home & Kitchen: Sellers using FBM as overflow during seasonal FBA capacity limits are reportedly the most affected segment
• Pet Supplies: Multiple mid-market operators in this category say they’ve received warnings on ASINs with FBM defect rates under 0.3%
• Sports & Outdoors: Particularly sellers carrying large, irregular-dimension SKUs that frequently exceed FBA dimensional weight thresholds and rely on FBM as a structural fulfillment alternative
• Health & Beauty: Sellers in this category, who often maintain FBM listings as a regulatory hedge, are reportedly receiving warnings at elevated frequency

Notably, pure-play FBA sellers and Amazon Vendor Central accounts appear to be entirely unaffected, which sources say is contributing to seller suspicion that the pattern is structural rather than incidental.

What Is Amazon Officially Saying?

Amazon’s Seller Relations press team did not respond to a request for comment before publication deadline. However, an unconfirmed internal memo — reportedly shared secondhand by an Amazon account manager during a paid seller consulting call — allegedly describes a “fulfillment reliability scoring update” as part of a broader initiative to “align customer delivery experience standards across all fulfillment channels.”

The language in that alleged memo, if accurate, would represent the clearest signal yet that Amazon is systematically tightening the conditions under which FBM remains a viable competitive option for high-volume sellers — particularly as the company continues scaling Amazon Warehousing & Distribution (AWD) as an upstream inventory layer feeding FBA.

“They’ve built AWD, they’ve built Buy with Prime, they’ve built the last-mile network. Every piece of infrastructure they’ve added in the last three years points in the same direction: they want total stack ownership. FBM disrupts that thesis.” — source close to Amazon’s third-party seller policy team, speaking anonymously

Are Aggregators and Agency Operators Changing Their Playbooks?

At least two mid-market Amazon aggregators are reportedly auditing their portfolio-wide FBM exposure in response. Thrasio, which has publicly discussed its ongoing brand portfolio rationalization through early 2026, is unconfirmed to be among them, though sources familiar with the company’s seller ops team say the topic has come up in internal quarterly reviews.

On the agency side, several Amazon-focused managed services firms — including reportedly Envision Horizons and Incrementum Digital — are allegedly advising clients to reduce FBM fallback listings to under 15% of total ASIN count while the situation remains unresolved. Neither agency responded to requests for comment before publication.

Meanwhile, some operators are reportedly exploring third-party fulfillment networks — including ShipBob’s Amazon-connected fulfillment nodes and Deliverr (now operating under Shopify’s fulfillment infrastructure) — as potential FBM carrier alternatives that might score better under Amazon’s new EDD accuracy standards, though the viability of this workaround is unconfirmed.

What Should Sellers Do Right Now?

Practitioners who have navigated previous Amazon policy shifts — including the 2023 inventory reimbursement changes and the 2024 FBA fee restructuring — are advising a measured but proactive response. The consensus emerging from seller communities points to several immediate actions:

• Audit Account Health dashboards weekly rather than monthly, specifically tracking the “Voice of the Customer” and “Delivery Performance” subsections for early warning signals
• Document FBM activation events — date, duration, carrier used, and EDD accuracy — so you have a defensible data record if you need to escalate to Seller Performance
• Review carrier selection for FBM listings against Amazon’s current partnered carrier list, as unconfirmed reports suggest non-partnered carriers are being scored more harshly under the new framework
• Avoid reactive listing deactivation of FBM backup listings without consulting an Amazon compliance specialist first, as sudden listing changes can themselves trigger algorithmic review flags
• Monitor Buy Box percentage on hybrid ASINs daily using tools like Helium 10’s Market Tracker or Jungle Scout’s Rank Tracker for early signals that Buy Box weighting has shifted

The broader concern among veteran operators isn’t just the immediate account health implications — it’s what this alleged shift signals about the medium-term landscape for sellers who have built fulfillment architectures around Amazon flexibility rather than Amazon dependency. If the pattern holds through Q3 2026, the hybrid FBA/FBM model that has served hundreds of thousands of sellers as a risk management tool for nearly a decade may be entering its final chapter as a mainstream strategy.

We’ll continue tracking this story. If you’re a seller who has received an Account Health warning connected to hybrid fulfillment in the past 60 days, contact our editorial team at tips@ecommercetimes.com.