San Mateo County voters decide four charter amendments on Tuesday, Nov. 3, 2026. Two of them are Measure J, which gives the Board of Supervisors 60 days instead of 30 to fill a vacancy in an elected county office and requires a public meeting before any appointment, and Measure AA, which adds a civil rights statement to the charter's preamble. Each needs a simple majority.

Why it matters: Measure J changes how the county fills offices such as sheriff, assessor or district attorney if one comes open mid-term. It does not apply to seats on the Board of Supervisors itself.

Measure J: vacancies in elected offices

Under Section 415 of the charter today, the board must either appoint someone or call a special election within 30 days of a vacancy in an elected office other than a supervisor seat. If it does neither, the county's elections officer must immediately order a special election, according to the county counsel's impartial analysis. There is no requirement for a public meeting before an appointment.

A yes vote:

  • Extends the deadline from 30 to 60 days.
  • Requires at least one noticed public meeting to take public comment on the appointment and the candidates' qualifications before the board appoints anyone.
  • Keeps the fallback: if the board doesn't act within 60 days, the elections officer still must call a special election.

The appointee would still serve the remainder of the term. A no vote keeps the 30-day rule with no required hearing.

Measure AA: a civil rights statement

Measure AA would add one paragraph to the charter preamble: "The County of San Mateo affirms its commitment to the dignity, civil rights, and equal protection of all County residents in a manner that promotes equity, fairness, inclusion, belonging, accessibility, and opportunity." The impartial analysis says it would not change any other part of the charter.

Where these came from

Both grew out of the county's 2026 Charter Review Committee, which the charter requires at least every eight years. The committee met eight times and made six recommendations; on May 19, 2026, the Board of Supervisors sent four of them to voters as separate measures, county records show. County staff told the board the cost of adding the measures to the November ballot was unknown but "could exceed $1,000,000." No official arguments for or against Measures J or AA were on file with VoterDecoder.

The other two county charter measures

The same package includes Measure L on extreme-weather resilience and Measure U, an independent redistricting commission for supervisor districts. See every race and measure in our Election 2026 guide.