(1) To determine whether a medically determinable impairment exists, we consider medical evidence from "acceptable medical sources." "Acceptable medical sources" include the following:

(a) For a physical impairment, a health professional licensed in Washington state or where the examination was performed:

(i) Medical doctor (MD);

(ii) Doctor of osteopathy (DO);

(iii) Doctor of optometry (OD) for visual disorders;

(iv) Doctor of podiatry (DP) for foot and ankle disorders;

(v) Physician assistant (PA) for impairments within their licensed scope of practice;

(vi) Advanced registered nurse practitioner (ARNP) for impairments within their licensed scope of practice;

(vii) Audiologist for impairments of hearing loss, auditory processing disorders, and balance disorders within their licensed scope of practice; and

(viii) Qualified speech-language pathologist, for purposes of establishing speech or language impairments.

(b) For a mental impairment, a health professional licensed in Washington state or where the examination was performed:

(i) Psychiatrist;

(ii) Psychologist;

(iii) Advanced registered nurse practitioner (ARNP) for impairments within their licensed scope of practice;

(iv) Physician assistant (PA) for impairments within their licensed scope of practice; and

(v) School psychologist or other licensed or certified individual who performs the same function as a school psychologist in a school setting for impairments of intellectual disability, learning disability, or borderline intellectual functioning.

(2) We accept medical evidence of how your impairment(s) affect your ability to function from "treating medical sources" once a diagnosis of a medically determinable impairment has been established by an "acceptable medical source" listed in subsection (1) of this section. "Treating medical sources" must be licensed to provide healthcare and include, but are not limited to:

(a) Physician treating you for a mental impairment;

(b) Clinical social worker;

(c) Mental health professional (MHP);

(d) Naturopath;

(e) Chiropractor;

(f) Physical therapist; and

(g) Chemical dependency professional (CDP) when requesting information on the effects of substance use disorders.

(3) "Other evidence" means information from sources not listed in subsections (1) and (2) of this section who can provide supporting documentation of functioning for impairments established by an "acceptable medical source" in subsection (1) of this section. Sources of "other evidence" may include public and private agencies, schools, family members, friends, caregivers, and employers.