In theory, CBT is freely available via the NHS to anyone in the UK who requires it. In practice, it is often extremely difficult to obtain CBT and even more difficult to find a CBT therapist with the skills, knowledge and experience required to work with autistic people.
In the UK, The British Association for Behavioural and Cognitive Psychotherapies (BABCP) keeps a register of all accredited therapists in the UK and The British Psychological Society (BPS) has a directory of chartered psychologists.
In the USA, the Academy of Cognitive Therapy and the National Association of Cognitive-Behavioral Therapists both have a directory of CBT therapists.
There are some nationally recognised qualifications for providers of CBT. For example, in the UK, The British Association for Behavioural and Cognitive Psychotherapies has developed accreditation criteria for minimum standards in CBT. However, such standards do not imply that accredited therapists will necessarily be competent to work with complex cases, for example, such as autistic people.