Fees & public finance
Nexus study
The technical study justifying an impact fee by connecting new development's burden to facility costs; AB 602 sets its content and adoption standards.
Definition
A nexus study is the analysis an agency adopts to justify an impact fee under the Mitigation Fee Act: it quantifies the existing level of service, identifies the capital improvements the fee will fund, and allocates to new development only its proportionate share of the cost. Since AB 602 (Gov. Code § 66016.5, 2021), studies for new or increased fees must be adopted at noticed public hearings, identify existing and proposed service levels, tie into capital planning, scale residential fees by square footage unless findings justify otherwise, and be refreshed on a defined cycle.
Why it matters in an underwrite
The nexus study is the discovery target in every fee fight. A stale, missing, or conclusory study is the soft spot a § 66020 protest attacks, and flat per-unit fees on small units — a 500 sq ft studio paying the same as a 1,400 sq ft three-bedroom — are the classic post-AB 602 vulnerability. Agencies must now post studies and schedules online, so demand and read them during feasibility, before the fee line hardens in the pro forma.
Sources & related guides
See also
See the term in the law itself
Read the controlling text in the Code Library, or ask the AI how it applies to your project.
Last reviewed 2026-07-29. General information, not legal advice.