Child Support in Mammoth Lakes and Mono County, California

Mono County has two Superior Court branches. The branch for your child support filing depends on where you live. The South County branch is at 100 Thompson Way in Mammoth Lakes. The North County branch, closer to the county seat, is at 278 Main St. in Bridgeport. Call (760) 924-5444 first. If you open a support matter at the wrong branch, you can lose weeks while the file is transferred.

California uses one child support guideline formula, Family Code 4055, no matter which Mono County courthouse hears the case. The formula compares each parent's net income with the share of time the child spends with each parent. Use the free calculator at childsupport.ca.gov before you file, and bring the number with you.

You have two ways to get an order. You can file Form FL-300 with an FL-150 income declaration at the branch assigned to your case. You can also ask the Mono County Local Child Support Agency to open the case for you. That office is on the second floor of the county building at 1290 Tavern Road in Mammoth Lakes, Tioga Room. It can establish parentage, set an order, and collect payments, generally without charging the parent who asks for help.

Mono County began accepting electronic filing in February 2025. That change is recent, so confirm the process with the clerk before you assume paper filing is no longer accepted. If you cannot afford the filing fee, ask for Form FW-001 to request a waiver.

How child support is calculated in California

California sets child support with a statewide uniform guideline (Family Code section 4055) that applies the same way in Mono County as everywhere else. The formula is based mainly on two things:

1. Both parents' net disposable incomes.
2. The percentage of time the child spends with each parent (the timeshare).

The guideline amount is presumed to be correct, and courts use a calculator to run the numbers. Because the result depends on accurate income, the Income and Expense Declaration (Form FL-150) you file is what drives your number.

Where child support cases are handled in Mono County

Child support in Mono County is handled through the Superior Court of California, County of Mono, and the county's Local Child Support Agency, which is part of the California Department of Child Support Services. There are two common paths:

1. Either parent files a Request for Order (Form FL-300) with an Income and Expense Declaration (Form FL-150) inside a divorce, parentage, or custody case.
2. The Local Child Support Agency opens a case to establish, collect, and enforce support, often at no cost to the parents.

Because courthouse and local agency office details change over time, confirm current details using the official California Courts court finder:

Find the Mono County Superior Court (official California Courts finder)

Local notes for Mono County

Mono County's two-branch system causes problems for many parents in this process. If you live near Mammoth Lakes, June Lake, or Lee Vining, the South County branch is almost certainly the right branch. If you live near Bridgeport, Walker, or Coleville, you likely belong at the North County branch instead. A wrong guess usually adds a mail delay to your case.

The Local Child Support Agency office at 1290 Tavern Road serves only Mono County. In a county this small, the office may keep shorter hours than a metro office, especially in winter when mountain passes close. Call ahead instead of driving in the cold.

A commissioner is listed as the officer who hears support matters. The court posts hours of 8:30 a.m. to 4:00 p.m. Monday through Thursday and 8:30 a.m. to noon on Friday. Staffing at a court this size can change, so check the self-help page before you plan a trip around those hours.

Official child support resources in Mono County

Superior Court of California, County of Mono (Mammoth Lakes Courthouse, South County Branch) handles child-support filings, located at 100 Thompson Way, Mammoth Lakes 93546. Phone: (760) 924-5444. Bridgeport Courthouse (North County Branch) at 278 Main St. handles the county seat courthouse.

E-filing is available. The court announced electronic filing became available in February 2025.

Mono County Self-Help Center / Family Law Facilitator (https://www.mono.courts.ca.gov/self-help-center-family-law-facilitator-office) can help with procedure and paperwork. Helps self-represented parents with forms and procedure; cannot give legal advice for your situation.

• Superior Court of California, County of Mono (Mammoth Lakes Courthouse, South County Branch)
• Mono County Self-Help / Family Law Facilitator
• Mono County Local Child Support Agency
• California Guideline Child Support Calculator
• Form FL-300 Request for Order
• Form FW-001 Request to Waive Court Fees

Local details reviewed August 2026. Offices and locations can change, so confirm with the official sites above before you file.

Mono County Child Support FAQs