Federal Circuit Reverses §101 Invalidity in Enfish v. Microsoft

Case: Enfish v. Microsoft (Fed. Cir., 2016) – software patent on a self-referential database.

Holding: Federal Circuit reversed §101 invalidity; claims not abstract under Alice/Mayo.

Key Principle: Software can improve computer functionality; not all software claims are inherently abstract.

Burden Shift: USPTO must now show the invention provides no technical improvement, rather than assuming abstractness.

Specification Matters: Clear description of technological improvements over prior art strengthens §101 eligibility.

Means-Plus-Function Claims: Can support patent eligibility if backed by sufficient algorithmic detail in the specification.