Medi-Cal does cover autism testing for adults, but the path is less direct than it is for children. An adult on Medi-Cal generally has three ways to get an autism diagnostic evaluation: through a Medi-Cal managed care plan’s mental health benefit, through the county Mental Health Plan’s specialty mental health services, or through a California Regional Center. Each has its own access point, and what happens after the diagnosis depends heavily on which door you came through.
Three Ways an Adult Can Get Evaluated
Your Medi-Cal Managed Care Plan
Managed care plans cover non-specialty mental health services for members with mild-to-moderate needs, and that benefit includes psychological testing “when clinically indicated to evaluate a mental health condition.” Autism spectrum disorder is a DSM-5 diagnosis, and the manual defines covered conditions as “mental health disorders, as defined by the current edition of the Diagnostic and Statistical Manual of Mental Disorders.” ASD is not on the excluded list, and the benefit explicitly reaches “potential mental health disorders not yet diagnosed.”1DHCS Medi-Cal. Non-Specialty Mental Health Services Manual
At least one plan spells this out. San Francisco Health Plan lists “evaluation for autism spectrum disorder” as a covered mild-to-moderate mental health benefit, managed through its behavioral health contractor Carelon Behavioral Health.2San Francisco Health Plan. Mental Health Services Other plans vary, so call your plan’s behavioral health line and ask specifically about an autism evaluation referral.
Expect to need a referral or order from a primary care physician. Some plans require prior authorization. Testing is usually approved only after a clinical interview has left a diagnostic question that testing can answer.1DHCS Medi-Cal. Non-Specialty Mental Health Services Manual Testing done purely for educational or vocational reasons, rather than to guide medical care, is excluded.
The County Mental Health Plan
County Mental Health Plans handle Medi-Cal specialty mental health services for people with more serious impairment. You do not need an existing diagnosis to get in. Adults qualify if they have significant impairment in social, occupational, or other important areas of functioning, or a reasonable probability of significant deterioration, tied to either a diagnosed mental health disorder or a suspected one.3Disability Rights California. Medi-Cal Specialty Mental Health Services Covered by County Mental Health Plans – Adults Covered services include diagnosis by licensed psychiatrists and psychologists.
Autism spectrum disorder (ICD-10 code F84.0) has been on the included diagnosis list for specialty mental health services since October 1, 2019.4DHCS. BHIN No. 20-043 ICD-10 Included Code Sets Update The Los Angeles County Department of Mental Health confirmed the change in a 2020 bulletin, while noting that adding ASD to the list does not create a new obligation for outpatient specialty mental health providers to treat clients with autism, and that ABA therapy is not covered under specialty mental health services.5County of Los Angeles Department of Mental Health. QA Bulletin 20-03 Updates to Included Allowable Diagnosis List
To start, call your county’s Mental Health Plan access line. The county cannot refuse an initial assessment to see whether you meet the criteria, and non-urgent outpatient mental health appointments must be offered within 10 business days of the request.3Disability Rights California. Medi-Cal Specialty Mental Health Services Covered by County Mental Health Plans – Adults
A Regional Center
California’s 21 Regional Centers offer free diagnostic evaluations for people with developmental disabilities, including autism.6California Department of Developmental Services. Eligibility An adult never diagnosed in childhood can still apply. The disability itself must have begun before age 18, but the formal diagnosis can come later. The evaluation costs nothing.
To qualify for ongoing Regional Center services after diagnosis, you must meet all three criteria under the Lanterman Developmental Disabilities Services Act: the disability began before age 18, it continues or is expected to continue indefinitely, and it is a “substantial disability” causing significant functional limitations in at least three of seven areas (self-care, language, learning, mobility, independent living, economic self-sufficiency, and self-direction).6California Department of Developmental Services. Eligibility A directory of Regional Centers is at dds.ca.gov.
One caveat. Regional Centers are the “payer of last resort” and generally do not fund services another entity is legally responsible for, treating Medi-Cal as a generic resource that must be used first.7California Department of Developmental Services. RC Services The Center will still conduct its own eligibility assessment, which includes diagnostic evaluation.
What Coverage Looks Like After the Diagnosis
A diagnosis opens fewer doors for adults than it does for children, and this is worth understanding before you start. Medi-Cal covers medically necessary behavioral health treatment, including applied behavior analysis (ABA), only for beneficiaries under 21.8DHCS. Behavioral Health Treatment That limit reflects the federal EPSDT benefit for people under 21, which does not extend to adults. California’s autism insurance mandate, SB 946, does not fill the gap: it explicitly excludes Medi-Cal contracts and policies.9California Legislature. SB 946
Other therapies are available but capped. Occupational therapy is typically limited to two visits per month, and physical therapy and speech therapy face similar restrictions. Coverage generally requires a reasonable expectation of significant improvement in a predictable period, or a maintenance program for a specific condition.10Health Net California. Autism Spectrum Disorders – Medi-Cal That improvement standard can be a hurdle when the goal is maintaining function.
Adults over 21 on Medi-Cal can still access diagnostic assessments, occupational therapy, physical therapy, speech-language therapy, assistive communication devices, and intensive communication interventions.11UCSF Office of Developmental Primary Care. Traditional Medi-Cal
If Your Evaluation Request Is Denied
You have appeal rights. Start with an internal appeal to the health plan, and include a letter from a physician prescribing the evaluation and explaining why it is medically necessary. Services that identify communication needs are likely to be considered medically necessary.11UCSF Office of Developmental Primary Care. Traditional Medi-Cal
If the plan denies the internal appeal, request a Medi-Cal Fair Hearing by phone at 1-800-952-5253 or through the California Department of Social Services website. If a managed care plan terminates services already in progress, you can request “aid paid pending” to keep receiving them while the appeal or hearing is decided.
Two other rules can help. Under California’s Timely Access Law, managed care plans must provide non-urgent specialist appointments within 15 business days of the request, and prior-authorization decisions must come in time to schedule within that window.11UCSF Office of Developmental Primary Care. Traditional Medi-Cal And CalAIM’s “No Wrong Door” policy, effective July 1, 2022, means members should get mental health services regardless of which delivery system they contacted first; providers can deliver an assessment and be reimbursed even if the member is later transferred to a different system.12DHCS. CalAIM Behavioral Health Initiative Practically, that means you should not be turned away for calling the “wrong” number.