Last refreshed: September 26, 2026
Direct Answer: The current Claude model lineup (September 2026) is Claude Fable 5.1 (1M context), Claude Opus 5.5, Claude Sonnet 5, and Claude Haiku 4.5. New releases ship automatically to Claude Code.
Anthropic ships new models roughly every few months, so the “latest model” question is really two questions: which model was released most recently, and which one should you be using. This page tracks both. The model releases below are listed newest first, and every entry is sourced from Anthropic’s official announcements or the Claude docs model overview.
Updated September 3, 2026
The two Claude Opus 5.5 models (standard + Extended Thinking) now ship automatically in Claude Code to Pro, Max, and API subscribers. This page reflects the current lineup.
Current Lineup (newest first)
Claude Opus 5.5 (standard + Extended Thinking)
Released: September 3, 2026 (announced alongside Claude Opus 5.5 Extended Thinking). The most capable Claude model for complex reasoning, agentic coding, and long-context analysis. Available through the Claude API, Claude Code, and Claude in Chrome.
Claude Fable 5.1
Released: August 27, 2026. Anthropic’s most capable Claude model for complex reasoning, agentic coding, and long-context analysis at launch, now succeeded by Opus 5.5 for flagship tasks. 1M-token context window. Available through the API, Claude Code, and Claude in Chrome.
Claude Sonnet 5
Released: August 2026. The balanced workhorse — strong reasoning at lower cost and latency than the flagship tier. Default model for many Claude Code workflows.
Claude Haiku 4.5
Released: October 1, 2025 (claude-haiku-4-5-20251001). Fast, cheap, 200K context. The model for high-volume simple tasks — classification, extraction, quick answers.
How Claude Code Gets New Models
New Claude models ship automatically in Claude Code — no manual upgrade step. When Anthropic releases a model (like Opus 5.5 on September 3), it appears in Claude Code for eligible subscribers without reinstalling or reconfiguring. This is why the “current model” question matters: your tooling quietly changes underneath you.
Models Anthropic Retired in 2026
- Claude Sonnet 4 / Opus 4 (original 4.0-generation): retired June 15, 2026. If your integrations still reference
20250514date-string IDs, they’re broken — migrate. - Claude Opus 4.1: retired September 2026 alongside the Opus 5.5 launch.
Frequently Asked Questions
What is the API model ID for Claude Opus 5.5?
The API model ID is claude-opus-5-5. It shipped 3 September 2026 and is available to Pro, Max, and API subscribers, including automatic availability in Claude Code.
Is Claude Haiku 4.5 being retired?
Anthropic’s 2026 consolidation removed older models (Sonnet 4 and Opus 4 on 15 June 2026, Opus 4.1 in September), but Haiku 4.5 remains the active fast model in the current lineup. Anthropic has not announced a retirement date for Haiku 4.5.
Is Claude Opus 5 still the current flagship model?
No — Claude Opus 5.5 (released 3 September 2026) succeeded it as Anthropic’s most capable model for complex reasoning and agentic coding. See our Claude Opus 5.5 pricing guide for plan and API details.
Which Claude model should I use right now?
For most work: Sonnet 5 (balanced). For the hardest reasoning and agentic coding: Opus 5.5. For high-volume simple tasks: Haiku 4.5. New models appear automatically in Claude Code when released.
Do new Claude models require reinstalling Claude Code?
No. New models ship automatically to eligible subscribers — no reinstall, no config change.
Where is the official model list?
Anthropic maintains the canonical list at platform.claude.com/docs/en/about-claude/models/overview.
Tracking Claude Models for Your Team?
At Tygart Media, we build AI systems that stay current with Anthropic’s releases. See our Claude implementation services or browse the full Claude pricing and plans guide.
Part of the complete guide: Claude Pricing, Plans & Limits
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