Mild—1 service delivery unit Minimum of 15–30 minutes per week	Moderate—2 service delivery units Minimum of 31–60 minutes per week
Severity of Disorder	Impairment minimally affects the individual's ability to communicate in school learning and/or other social situations as noted by at least one other familiar listener, such as teacher, parent, sibling, peer.	Impairment interferes with the individual's ability to communicate in school learning and/or other social situations as noted by at least one other familiar listener.
Articulation/Phonology	Intelligible over 80% of the time in connected speech. No more than 2 speech sound errors outside developmental guidelines. Student may be stimulable for error sounds.	Intelligible 50–80% of the time in connected speech. Substitutions and distortions and some omissions may be present. There is limited stimulability for the error phonemes.
Language	The student demonstrates a deficit in receptive, expressive, or pragmatic language as measured by two or more diagnostic procedures/standardized tests. Performance falls from 1 to 1.5 standard deviations below the mean standard score.	The student demonstrates a deficit in receptive, expressive or pragmatic language as measured by two or more diagnostic procedures/standardized tests. Performance falls from 1.5 to 2.5 standard deviations below the mean standard score.
Fluency	2–4% atypical disfluencies within a speech sample of at least 100 words. No tension to minimal tension. Rate and/or Prosody: Minimal interference with communication.	5–8% atypical disfluencies within a speech sample of at least 100 words. Noticeable tension and/or secondary characteristics are present. Rate and/or Prosody: Limits communication.
Voice	Voice difference including hoarseness, nasality, denasality, pitch, or intensity inappropriate for the student's age is of minimal concern to parent, teacher, student, or physician. Medical referral may be indicated.	Voice difference is of concern to parent, teacher, student, or physician. Voice is not appropriate for age and sex of the student. Medical referral may be indicated.
	Severe—3 service delivery units Minimum of 61–90 minutes per week	Profound—5 service delivery units Minimum of 91+ minutes per week
Severity of Disorder	Impairment limits the individual's ability to communicate appropriately and respond in school learning and/or social situations. Environmental and/or student concern is evident and documented.	Impairment prevents the individual from communicating appropriately in school and/or social situations.
Articulation/Phonology	Intelligible 20–49% of the time in connected speech. Deviations may range from extensive substitutions and many omissions to extensive omissions. A limited number of phoneme classes are evidenced in a speech-language sample. Consonant sequencing is generally lacking. Augmentative communication systems may be warranted.	Speech is unintelligible without gestures and cues and/or knowledge of the context. Usually there are additional pathological or physiological problems, such as neuromotor deficits or structural deviations. Augmentative communication systems may be warranted.
Language	The student demonstrates a deficit in receptive, expressive or pragmatic language as measured by two or more diagnostic procedures/standardized tests (if standardized tests can be administered). Performance is greater than 2.5 standard deviations below the mean standard score. Augmentative communication systems may be warranted.	The student demonstrates a deficit in receptive, expressive or pragmatic language that prevents appropriate communication in school and/or social situations. Augmentative communication systems may be warranted.
Fluency	9–12% atypical disfluencies within a speech sample of at least 100 words. Excessive tension and/or secondary characteristics are present. Rate and/or Prosody: Interferes with communication.	More than 12% atypical disfluencies within a speech sample of at least 100 words. Excessive tension and/or secondary characteristics are present. Rate and/or Prosody: Prevents communication.
Voice	Voice difference is of concern to parent, teacher, student or physician. Voice is distinctly abnormal for age and sex of the student. Medical referral is indicated.	Speech is largely unintelligible due to aphonia or severe hypernasality. Extreme effort is apparent in production of speech. Medical referral is indicated.

Notes. By the age of 7 years, the student's phonetic inventory is completed and stabilized (Hodson, 1991). Adverse impact on the student's educational performance must be documented. If the collaborative consultation model of intervention is indicated at the meeting, the student receives one additional service delivery unit.

Source: Illinois State Board of Education. (1993). Speech-language impairment: A technical assistance manual. Springfield: Author. Reprinted by permission.

Editor's Note. The state or district matrix may be used as a general guideline, but the amount of service per week is determined by the IEP team to meet the individual needs of the students.