DID Best Practice Guidelines

An authorized provider conducting a determination of intellectual disability (DID), or endorsing a previous DID, must use the DID Best Practice Guidelines (PDF).

The DID Best Practice Guidelines were developed by the Texas Department of Aging and Disability Services (DADS) as required by 40 Texas Administrative Code (TAC), Chapter 5, Subchapter D, Diagnostic Assessment.

HHSC maintains a formatted version of Subchapter D on its website to enhance public access to program information. The Texas Register and the Texas Administrative Code remain the official sources for all rules.


FAQ Acronyms

  • ABAS — Adaptive Behavior Assessment System
  • ABL — Adaptive behavior level
  • AP — Authorized provider
  • ASD — Autism spectrum disorder
  • BPG — Best Practice Guidelines
  • CAP — Certified authorized provider
  • CARE — Client Assignment and Registration
  • CFC — Community First Choice
  • CLASS — Community Living Assistance and Support Services
  • CFR — Code of Federal Regulations
  • DID — Determination of intellectual disability
  • DBMD — Deaf Blind with Multiple Disabilities
  • DSM — Diagnostic and Statistical Manual of Mental Disorders
  • GR — General Revenue
  • HCS — Home and Community-based Services Waiver Program
  • HHS — Health and Human Services
  • ICD — International Statistical Classification of Diseases and Related Health Problems
  • ICF/IID — Intermediate care facility for individuals with an intellectual disability and related conditions
  • ID — Intellectual disability
  • IDD — Intellectual and developmental disability
  • ID/RC — Intellectual Disability and Related Conditions Assessment
  • IQ — Intelligence quotient
  • LAR — Legally authorized representative
  • LIDDA — Local intellectual and developmental disability authority
  • LOC — Level of care
  • NF — Nursing facility
  • PASRR — Preadmission Screening and Resident Review
  • RC — Related condition
  • RCESI — Related Condition Eligibility Screening Instrument
  • TAC — Texas Administrative Code
  • TxHmL — Texas Home Living
  • WAIS — Wechsler Adult Intelligence Scale
  • WISC — Wechsler Intelligence Scale for Children
  • VABS — Vineland Adaptive Behavior Scales

DID General Guidelines

  1. If I diagnose a client with ID per DSM-5 standards at age 17 even though their IQ is high enough they don’t currently qualify for services, can they qualify for services in the future if the IQ and adaptive levels meet the standards?
    If, upon initial testing, an individual’s IQ score does not meet or fall below the maximum allowed IQ score, but does so in subsequent testing, the DID report should describe the previous test results (per DID BPG, Item 13(b)) and provide an explanation or justification why current results are considered valid and thus an accurate reflection of the individual’s functioning level.

Assessment Instruments and Tests General Guidelines

  1. Which adaptive behavior tests are accepted?
    For examples of tests considered valid and reliable see the DID BPG Item 2(a).

Individuals with a Communication Impairment

  1. Is the Leiter International Performance Scale, a nonverbal test for kids who are very young and nonverbal, still acceptable test?
    Yes, the Leiter may be used if clinically appropriate.

Use of Brief Assessment Instruments and Tests

  1. What would be a scenario when a brief IQ test would be used?
    Item 2(e) of the DID BPG provides examples of brief IQ tests (e.g., the Slosson) and certain limited situations in which a brief test may be warranted.
  2. Is the Slosson Intelligence Test still acceptable for use with individuals who are unable to take a more comprehensive assessment such as the WAIS or WISC? It is the only test that we have found so far that gives IQ scores within the lower severe and profound IQ ranges and measures both verbal and non-verbal abilities. 
    Use of a brief test of intelligence to establish an individual’s initial eligibility programs is discouraged; however, Item 2(e) of the DID BPG provides examples of brief IQ tests and certain limited situations in which a brief test, including the Slosson, may be warranted. It also requires an AP to explain/justify the use of a brief test in the DID report. Item 2(f) of the DID BPG provides additional guidance when a standardized intellectual assessment cannot be administered. Finally, to ensure the test results are valid, Item 2(a) requires the use of the most current version of a test.

When a Standardized Intellectual Assessment Cannot be Successfully Administered

  1. Is a CAP allowed to exercise clinical judgment in the selection of appropriate adaptive instruments when conducting DID assessments and the need for an “estimated” IQ occurs? For instance, we find the ABAS-3 to be a highly useful instrument that yields rich information regarding the various domains of an individual’s adaptive functioning. It appears to us that it would be an acceptable instrument to provide an “estimated” IQ.
    Per Item 2(f) in the DID BPG, if a standardized intellectual assessment cannot be successfully administered, APs (including CAPS) may provide an estimate of the individual’s IQ score, or IQ score equivalent, with clinical justification.
  2. Do current DIDs with a diagnosis of Unspecified ID require a VABS-II be completed to give an estimated IQ score instead of using 19 as done previously?
    If a standardized intellectual assessment cannot be successfully administered, an AP shall provide an estimated IQ score using a developmental rating scale or an Adaptive Behavior Composite (e.g., provided by the VABS). (See Item 2(f) of the DID BPG.)

    The ID/RC screen in CARE does not permit entry of an IQ-score lower than 19. In lieu of modifying CARE, HHS will revise instructions for the ID/RC to provide clarification on the use of 19 for individuals with an IQ below 19.

Establishing the Origination of ID During the Developmental Period

  1. Can evidence of onset be based on verbal feedback provided by family if no actual documentation is available (especially when assisting older individuals whose records might no longer be available)? Can a family member’s information be accepted for an older person if there was no testing or verification of onset age? I have a client who has a suspected ID diagnosis as his IQ was 60. We are trying to access services for him, but were informed we need his school records indicating he was in special education classes in order to access these services. We are having difficulty accessing these records, and I was wondering if there are other options we could pursue in completing his ID diagnosis.
    The DID report must include evidence supporting the origination before age 18. As noted in Item 5 of the DID BPG, an AP may use reports by other people, including the individual’s family and friends. School records may inform; however, the term “special education” alone may imply services for ID, severe and emotional disturbance, or a learning disorder. If available, the DID report should provide examples (e.g., the individual did not speak in sentences until age five). The AP is reminded to rule out other possible causes of current functioning (e.g., mental illness). For more guidance see Item 13(b) in the DID BPG.
  2. Should "provisional" IDD be used if the only source of developmental history is the client themselves?
    No. A DID is used to determine eligibility; as such, HHS would be unable to accept a DID with findings that are inconclusive (i.e., provisional). 

    As stated in Item 5 of the DID BPG, an authorized provider must make efforts to obtain as  much supporting evidence as possible and include in the DID report a detailed description of the information and references used to make that determination. Absent any record, collateral contact (e.g., family, acquaintances), etc., an AP must use clinical judgment in deciding if the individual is a reliable source.

Endorsement of a Previous Assessment

  1. If a client’s IQ is in the normal range and there is no question of ID, is it okay to endorse a brief IQ test?
    As stated in Item 2(e) of the DID BPG, a brief test may be appropriate for an individual that presents with a well-established, documented testing history based on broad-based batteries and the results of a brief test you administer are consistent with testing history.
  2. Is a non-video telephone interview acceptable for endorsement if face to face interview cannot occur?
    The rule does not specify how the interview is conducted; therefore, this approach would be acceptable, assuming the individual is able to verbally communicate with the authorized provider.
  3. Did you say simply phone contact not face to face would be okay for endorsement?
    The requirement for an authorized provider conducting a review and endorsement to interview an individual may be accomplished by phone (e.g., FaceTime) or computer (e.g., Skype). However conducted, the interview must be with the individual. Although an interview with an individual’s guardian or family member is indicated, it would be in addition to (and not a substitute for) an interview with the individual.

    Regardless of how an interview is conducted, the choice of medium must align with an individual’s skills and ability to communicate (e.g., telephoning an individual who is non-verbal is inappropriate and would not satisfy the expectation).
  4. To clarify, testing is required for all individuals under the age of 22 for all programs across the board and not just CFC non-waiver, correct?
    Yes, in determining eligibility for ICF/IID, HCS, TxHmL, GR-funded services, and CFC non-waiver services, a new DID is required if the previous assessment was completed when the individual was under age 22 and the testing is more than five years old.
  5. Can a state hospital assist a LIDDA in completing a DID? 
    As permitted by statute, qualified clinical staff (regardless of affiliation) may conduct an evaluation but it must be endorsed by an AP associated with the LIDDA. Endorsement of a previous DID is appropriate only if an AP interviews the individual; reviews the previous DID; and determines the previous evaluation meets all the requirements of a DID and is a valid reflection of the individual’s current functioning. APs are reminded to attach a copy of the previous DID being endorsed.

Eligibility for GR Services Based on ID

  1. If someone is coming in for a GR evaluation, should I be listing whether or not they are eligible for Medicaid Waiver programs?
    As noted in Item 13(g) of the DID BPG, an authorized provider offers recommendations responsive to the identified purpose. In the example given, we assume the person has not received an offer of waiver services and is not a member of an HCS waiver program target group.  If that is the case, addressing an individual’s eligibility for a Medicaid program in advance of an offer to enroll would be premature. 
  2. Is the RCESI required for eligibility for GR services?
    No, the RCESI is not required for GR services (the presence of an RC is applicable to Medicaid programs only).

Eligibility for GR Services Based on ASD

  1. What exactly is meant by structured observation for ASD diagnosis? Or can you simply review the DADS criteria for basing eligibility on ASD.
    A “structured behavioral observation” refers to an observation period that allows for the opportunity to identify ASD diagnostic criteria, including the use of some on-demand activities. This observation may be similar to a structured clinical interview in that there are diagnostic components to cover, but it’s not structured in the sense that it is of a particular order and length of time. But it also is not a completely informal casual observation of a child during free play or self-directed activity, instead you would observe the individual during various “demand” situations, noting a wide variety of elements (e.g., response style, capacity for focused attention, frustration tolerance, reciprocity of communication, initiation of conversation, expression of emotions, eye contact/other body language, stereotypy movements, response to change/rigidity, interaction with objects such as toys if a child). You may note sensory issues and range of interests as well, although you may get a better understanding of those through reported history versus trying to observe everything.
  2. I did not hear/see discussion of best practices for ASD determination? ASD evidence + IQ possibly above 69, but ABL at least Level 1?
    An individual diagnosed with ASD based on criteria described in the DSM-5 may be determined eligible for GR-funded services without regard to the IQ score or ABL. Recommended practices are described in Item 8(b) of the DID BPG. Also see the DID BPG Summary Chart, page 17.


  1. To clarify, if we have ICF/IID providers who have accepted individuals in to their facilities, they will have to arrange for the individuals to see us as the LIDDA before we can authorize the ID/RC?
    Correct. In accordance with Title 40, TAC, Chapter 9, Subchapter E, §9.244 Applicant Enrollment in the ICF/MR Program: (a) Except as provided in subsection (b) of this section, only a LIDDA may request enrollment of an applicant by DADS. (b) A program provider may request enrollment of an applicant by DADS in accordance with subsection (k) of this section if the applicant: (1) has received ICF/MR services from a non-state operated facility during the 180 days before the enrollment request; and (2) is not moving from or seeking admission to a state school or state center.
  2. The DSM-IV diagnosis of Asperger’s assumes a higher IQ. If eligibility under LOC I is limited to a diagnosis of an RC with an IQ of 75 or less, would a person with Asperger’s be ineligible for services?
    If a person has an RC (e.g., Asperger’s) based on ICD-10 (not DSM as the question indicates) with an IQ score over 75, he or she would not meet LOC I for Medicaid programs.

    However, if the same person has an ABL of II, III, or IV, he or she may meet LOC VIII for Medicaid programs. LOC VIII does not take IQ into account. Similarly, for GR services, a diagnosis of ASD (DSM-5 terminology) alone would be sufficient with no IQ or ABL requirement. The AP determines an ASD diagnosis based on history and appropriate screening or best practice tools. (See DID BPG Summary Chart, page 17).
  3. Just to make sure, if an individual has been diagnosed with autism with an IQ of 85 but has an ABL of II, they will qualify with an LOC VIII. Right?
    Correct. LOC VIII is applicable to Medicaid programs and department rules require an RC diagnosis (e.g., autism) to be made by a licensed physician. Federal policy requires an RC diagnosis to be based on ICD-10.
  4. Would you explain LOC VIII and how a person does not need to have a diagnosis of ID to be eligible for services? Since LOC VIII requires a physician’s diagnosis, does the diagnosis or physician’s statement stand alone, without the AP needing to follow up with testing?
    LOC VIII is based on the person having a primary diagnosis of an RC diagnosed by a licensed physician, in addition to meeting the other RC eligibility criteria. Although IQ is not part of the determination of LOC VIII, the AP is still required to conduct a new DID (or endorsement, if appropriate) in accordance with Title 40, TAC, Chapter 5, Subchapter D, concerning Diagnostic Assessment. The AP formally assesses the person’s IQ and ABL and conducts additional testing, if indicated. For example, the AP may need to rule out or confirm autism. The LIDDA designee (e.g., AP or other staff) completes Form 8662 RCESI to attest the date of onset and other requirements. The AP uses the completed RCESI (and results of other testing, if indicated) to inform a final determination the person meets all eligibility requirements for an RC and documents those findings in the DID report.

    Example: an NF resident has cerebral palsy diagnosed by a physician; the condition manifested before age 22; and the resident has always tested in the “normal” range of intellectual functioning. The NF resident meets LOC VIII despite the higher IQ score if he meets all the criteria for an RC. (See DID BPG Footnote #4, page 13.)
  5. If ASD is used as the RC for eligibility under LOC VIII, must the ASD be diagnosed by a physician? Must every RC be diagnosed by a doctor? 
    Any time eligibility is based wholly, or in part, on an RC, the diagnosis must be made by a licensed physician as required by Title 40, TAC, Chapter 9, Subchapter E, Sections 9.238 and 9.239.

    This question asks about ASD which appears in DSM-5 (the diagnostic reference for GR services). An LOC VIII requires the person to have an RC based on ICD-10 (the diagnostic reference for Medicaid programs). ICD-10 does not use ASD. (See DID BPG, Item 9 and Summary Chart, page 17).
  6. What if there is a conflict between physician’s diagnosis and AP’s assessment?
    If the AP’s findings are inconsistent with the licensed physician’s primary diagnosis, it may be appropriate to request the physician to reassess. If that is not possible or the physician declines, the DID report should acknowledge the physician’s diagnosis, explain why the AP is unable to support or corroborate the diagnosis, and provide supporting evidence for the AP’s findings.

    The LIDDA is the front door to services for ICF/IID, HCS, TxHmL, and CFC non-waiver services. As such, an AP conducting DIDs and endorsements on behalf of the LIDDA has a responsibility to ensure accurate determinations of eligibility.

    The reader is reminded if an individual or the individual’s LAR does not accept the DID, in accordance with Title 40, TAC, Chapter 5, Subchapter D, Section 5.155(i)(1)(A), the person who requested the DID has the right to an additional, independent DID conducted at the person’s expense if the person questions the validity or results of the DID; and an administrative hearing to contest the findings of the DID per Title 40, TAC, Chapter 4, Subchapter D, relating to Administrative Hearings under the Texas Health and Safety Code, Title 7, Subtitle D.

    If the AP conducted an endorsement (in lieu of a DID), in accordance with Title 40, TAC, Chapter 5, Subchapter D, Section 5.156(e)(2)(B), the individual or LAR has the right to an administrative hearing to contest the findings of the DID, as described in Title 40, TAC, Chapter 4, Subchapter D, relating to Administrative Hearings under Texas Health and Safety Code, Title 7, Subtitle D; and the opportunity to have the AP employed by or contracting with the LIDDA conduct a diagnostic assessment (i.e., new DID) at no expense to the individual or LAR.
  7. Is it sufficient for a physician to give an attestation with just the name of the diagnosis but no code?
    The physician’s attestation on the diagnostic name/description may be sufficient if the diagnosis is based on ICD-10 and LIDDA staff (e.g., AP) is able to locate the correct, corresponding ICD-10 diagnostic code.
  8. Does it matter if the medical documentation is old?
    Assuming a given diagnosis is valid and current, HHS does not impose an arbitrary time requirement or expiration date. (See DID BPG, Footnote #4 for the CFR definition requiring the condition to be likely to continue indefinitely.) However, a diagnosis likely would need to be updated if the initial diagnosis was based on an older version of the ICD. Also the list of approved RCs is subject to change by HHS, requiring the physician to update a diagnosis to ensure the individual remains eligible.
  9. When determining eligibility for an RC, will I need to use Form 8662 for any program?
    Per Form 8662 instructions, the RCESI is used to determine programmatic eligibility for the ICF/IID program, ICF/IID waiver programs (HCS, TxHmL, CLASS, and DBMD), and CFC non-waiver services, when the applicant does not have a diagnosis of ID at the time of application. This form is not used to determine eligibility for GR-funded services.
  10. Who would complete Form 8662, psychologist or LIDDA?
    A LIDDA may delegate this task to whomever the LIDDA deems appropriate, including but not limited to an AP or service coordinator.
  11. Does a medical diagnosis for an NF resident need to be done by a physician instead of sending the consumer for testing with a psychologist who is going to defer to the physician anyway?
    The diagnosis of an RC must be made by a licensed physician. The AP’s role is to conduct the adaptive behavior assessment and ensure the other RC criteria is met.

Eligibility for the HCS and TxHmL Waiver Programs (Also see FAQs for ICF/IID LOC I and LOC VIII)

  1. I have a young lady who was previously in HCS and went into an ICF/IID and is now going back into HCS, but her DID is from 2000 and she is now 22. This means she will need a new DID before entering back into the HCS program, right?
  2. Does an individual transitioning from an NF have a different IQ requirement when enrolling in Medicaid Waivers such as HCS? I recall years ago that some information at that level had been discussed during a PASRR training.
    An individual who enrolls in HCS as a diversion from NF admission or who enrolls in HCS directly from an NF must meet the ICF/IID LOC I or LOC VIII criteria. Note that LOC VIII does not have an IQ requirement. For any other individual who enrolls in HCS, eligibility must be based on LOC I criteria.

Eligibility for CFC Non-Waiver with ICF/IID LOC

  1. The first presenter stated that there is no rule (other than CFC non-waiver) stating that DIDs must be updated every 5 years. The second presenter stated it does. Is that based on BPG?
    Yes, the DID BPG address on-going eligibility for CFC non-waiver services. (See DID BPG, Item 11.)

DID Report Elements

  1. Can you send a report template that includes the essential required statements/lists from which report writers can individualized/personalized for the individual?
    The DID report template is provided in the DID BPG. (See Item 13 of the DID BPG.)
  2. I had a client come in who was clearly born male, but identifies as a female, had his/her name legally changed to a female name, requested to be called “she”, was wearing female clothing, and was in the process of physically transitioning  into a female (currently taking female hormones and had plans to be surgically altered).  What gender do I put in the system?
    Female. However, historical information such as this should be included in the DID report as part of either the background or current information about the individual.
  3. If an AP identifies an RC but does not yet have the physician’s attestation and cannot obtain it within the 30 days by which the DID report must be completed, should the AP conclude the person is ineligible or state the person is eligible, pending the attestation?
    APs are discouraged from concluding the person is ineligible for a Medicaid program if the physician’s statement was not received within the timeframe required for completing the DID report. The DID BPG do not address this scenario; however, HHS recommends the DID report include a statement the person meets the RC requirements pending receipt of physician documentation.


  1. Is a DID a billable activity for a CAP?
    A CAP is not licensed to practice independently. As such, a CAP is not eligible to be an approved Medicaid provider nor can they directly bill Medicaid for their services. As of May 2017, the only billing options include:
    1. The AP is a psychologist licensed to practice independently in Texas and has a Medicaid provider identification number; and the individual for whom a DID is conducted is a Medicaid recipient. Medicaid will reimburse for the testing to complete a DID.
    2. The individual for whom a DID is conducted is admitted to an NF and the LIDDA staff conducting the PASRR Evaluation refers the individual for a DID because the LIDDA staff has determined that there is insufficient documentation in the individual’s record to rule out the individual has an ID or an RC. HHS will reimburse the LIDDA for the DID using Form 1048.
  2. What is a DID "update?” That term is used here when we are required to do an update for enrollment in HCS or TxHmL.
    DID update is an unofficial term used by some LIDDAs to refer to a report in which only a portion of the diagnostic assessment is updated. The term does not appear in the DID BPG or department rules or policies. In order to recommend eligibility for HCS, HHS requires a LIDDA to complete a new DID or endorse a previous one. As part of a DID, the BPG allow an AP to validate previous assessment and test results, if appropriate. (See DID BPG, Item 3).

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Questions about the DID Best Practice Guidelines can be sent to didbpg@hhsc.state.tx.us.