Across the 24-month window May 2024 to April 2026, every major foundation-model provider (Anthropic, OpenAI, Google, AWS Bedrock, Azure OpenAI) experienced at least one multi-hour outage that exceeded the SLA-credit threshold defined in their published terms. The procurement-defensible posture is multi-provider routing with documented failover and hard-dollar incident liability above the standard SLA-credit cap. Three architectural patterns dominate 2026 production deployments: gateway abstraction (LiteLLM, OpenRouter, Portkey), provider-side regional failover (partial mitigation), and explicit multi-provider provisioning at the application layer.

30-day Holding-up cadence — the operational record ages monthly, not quarterly. Trigger conditions: a foundation-model provider publishing sustained 99.99% across 12 consecutive months; regulatory development requiring multi-provider provisioning for high-risk deployments; landmark vendor outage with material customer harm and follow-on litigation. Indicative procurement-fee figures in the body marked source:our-estimate. Sister claims: AM-026 (60-question RFP), AM-138 (post-enforcement MSA), AM-123 (observability), RES-005 (MSA red-team checklist).