The two-tier framework divides ESI into accessible sources subject to ordinary discovery obligations and not reasonably accessible sources a party may decline to produce absent good cause.
It was introduced by the 2006 federal amendments addressing electronic discovery.
Alternative Names:
Tiered Discovery, Two-Tiered ESI Discovery
Why it Matters?
The framework gives producing parties a structured basis for limiting scope, but it depends on having identified and characterized sources credibly. A party that cannot describe its data landscape cannot invoke the second tier, which is why a current data map matters more than any argument made later. The distinction has narrowed over time as storage and search technology improved.
Frequently Confused with
Related terms
Frequently asked questions
What distinguishes the two tiers?
What is required to invoke the second tier?
