2024 ICD-10-CM Diagnosis Code T40.496D

Underdosing of other synthetic narcotics, subsequent encounter

ICD-10-CM Code:
T40.496D
ICD-10 Code for:
Underdosing of other synthetic narcotics, subs
Is Billable?
Yes - Valid for Submission
Chronic Condition Indicator: [1]
Not chronic
Code Navigator:

Code Classification

  • Injury, poisoning and certain other consequences of external causes
    (S00–T88)
    • Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances
      (T36-T50)
      • Poisoning by, adverse effect of and underdosing of narcotics and psychodysleptics [hallucinogens]
        (T40)

T40.496D is a billable diagnosis code used to specify a medical diagnosis of underdosing of other synthetic narcotics, subsequent encounter. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2023 through September 30, 2024. The code is exempt from present on admission (POA) reporting for inpatient admissions to general acute care hospitals.

This code describes a circumstance which influences the patient's health status but not a current illness or injury. The code is unacceptable as a principal diagnosis.

T40.496D is a subsequent encounter code, includes a 7th character and should be used after the patient has completed active treatment for a condition like underdosing of other synthetic narcotics. According to ICD-10-CM Guidelines a "subsequent encounter" occurs when the patient is receiving routine care for the condition during the healing or recovery phase of treatment. Subsequent diagnosis codes are appropriate during the recovery phase, no matter how many times the patient has seen the provider for this condition. If the provider needs to adjust the patient's care plan due to a setback or other complication, the encounter becomes active again.

Clinical Classification

Clinical Information

  • Alphaprodine

    an opioid analgesic chemically related to and with an action resembling that of meperidine, but more rapid in onset and of shorter duration. it has been used in obstetrics, as pre-operative medication, for minor surgical procedures, and for dental procedures. (from martindale, the extra pharmacopoeia, 30th ed, p1067)
  • Buprenorphine

    a derivative of the opioid alkaloid thebaine that is a more potent and longer lasting analgesic than morphine. it appears to act as a partial agonist at mu and kappa opioid receptors and as an antagonist at delta receptors. the lack of delta-agonist activity has been suggested to account for the observation that buprenorphine tolerance may not develop with chronic use.
  • Buprenorphine, Naloxone Drug Combination

    a pharmaceutical preparation that combines buprenorphine, an opioid analgesics with naloxone, a narcotic antagonists to reduce the potential for narcotic dependence in the treatment of pain. it may also be used for opioid substitution therapy.
  • Butorphanol

    a synthetic morphinan analgesic with narcotic antagonist action. it is used in the management of severe pain.
  • Dextropropoxyphene

    a narcotic analgesic structurally related to methadone. only the dextro-isomer has an analgesic effect; the levo-isomer appears to exert an antitussive effect.
  • Levopropoxyphene

    a propionate derivative that is used to suppress coughing.
  • Levorphanol

    a narcotic analgesic that may be habit-forming. it is nearly as effective orally as by injection.
  • Meperidine

    a narcotic analgesic that can be used for the relief of most types of moderate to severe pain, including postoperative pain and the pain of labor. prolonged use may lead to dependence of the morphine type; withdrawal symptoms appear more rapidly than with morphine and are of shorter duration.
  • Nalbuphine

    a narcotic used as a pain medication. it appears to be an agonist at kappa receptors and an antagonist or partial agonist at mu receptors.
  • Pentazocine

    the first mixed agonist-antagonist analgesic to be marketed. it is an agonist at the kappa and sigma opioid receptors and has a weak antagonist action at the mu receptor. (from ama drug evaluations annual, 1991, p97)
  • Phenazocine

    an opioid analgesic with actions and uses similar to morphine. (from martindale, the extra pharmacopoeia, 30th ed, p1095)

Coding Guidelines

Underdosing refers to taking less of a medication than is prescribed by a provider or a manufacturer's instruction. Codes for underdosing should never be assigned as principal or first-listed codes. If a patient has a relapse or exacerbation of the medical condition for which the drug is prescribed because of the reduction in dose, then the medical condition itself should be coded.

The appropriate 7th character is to be added to each code from block Poisoning by, adverse effect of and underdosing of narcotics and psychodysleptics [hallucinogens] (T40). Use the following options for the aplicable episode of care:

  • A - initial encounter
  • D - subsequent encounter
  • S - sequela

Code Edits

The Medicare Code Editor (MCE) detects and reports errors in the coding of claims data. The following ICD-10-CM Code Edits are applicable to this code:

  • Unacceptable principal diagnosis - There are selected codes that describe a circumstance which influences an individual's health status but not a current illness or injury, or codes that are not specific manifestations but may be due to an underlying cause. These codes are considered unacceptable as a principal diagnosis.

Present on Admission (POA)

T40.496D is exempt from POA reporting - The Present on Admission (POA) indicator is used for diagnosis codes included in claims involving inpatient admissions to general acute care hospitals. POA indicators must be reported to CMS on each claim to facilitate the grouping of diagnoses codes into the proper Diagnostic Related Groups (DRG). CMS publishes a listing of specific diagnosis codes that are exempt from the POA reporting requirement. Review other POA exempt codes here.

CMS POA Indicator Options and Definitions

POA IndicatorReason for CodeCMS will pay the CC/MCC DRG?
YDiagnosis was present at time of inpatient admission.YES
NDiagnosis was not present at time of inpatient admission.NO
UDocumentation insufficient to determine if the condition was present at the time of inpatient admission.NO
WClinically undetermined - unable to clinically determine whether the condition was present at the time of inpatient admission.YES
1Unreported/Not used - Exempt from POA reporting. NO

Replacement Code

T40496D replaces the following previously assigned ICD-10-CM code(s):

  • T40.4X6D - Underdosing of other synthetic narcotics, subs encntr

Table of Drugs and Chemicals

The parent code T40.496 of the current diagnosis code is referenced in the Table of Drugs and Chemicals, this table contains a classification of drugs, industrial solvents, corrosive gases, noxious plants, pesticides, and other toxic agents.

According to ICD-10-CM coding guidelines it is advised to do not code directly from the Table of Drugs and Chemicals, instead always refer back to the Tabular List when doing the initial coding. Each substance in the table is assigned a code according to the poisoning classification and external causes of adverse effects. It is important to use as many codes as necessary to specify all reported drugs, medicinal or chemical substances. If the same diagnosis code describes the causative agent for more than one adverse reaction, poisoning, toxic effect or underdosing, utilize the code only once.

Substance Poisoning
Accidental
(unintentional)
Poisoning
Accidental
(self-harm)
Poisoning
Assault
Poisoning
Undetermined
Adverse
effect
Underdosing
AlphaprodineT40.491T40.492T40.493T40.494T40.495T40.496
AnileridineT40.491T40.492T40.493T40.494T40.495T40.496
BezitramideT40.491T40.492T40.493T40.494T40.495T40.496
BuprenorphineT40.491T40.492T40.493T40.494T40.495T40.496
ButorphanolT40.491T40.492T40.493T40.494T40.495T40.496
DextropropoxypheneT40.491T40.492T40.493T40.494T40.495T40.496
EptazocineT40.491T40.492T40.493T40.494T40.495T40.496
EthoheptazineT40.491T40.492T40.493T40.494T40.495T40.496
IsonipecaineT40.491T40.492T40.493T40.494T40.495T40.496
LevopropoxypheneT40.491T40.492T40.493T40.494T40.495T40.496
LevorphanolT40.491T40.492T40.493T40.494T40.495T40.496
MeperidineT40.491T40.492T40.493T40.494T40.495T40.496
NalbuphineT40.491T40.492T40.493T40.494T40.495T40.496
PentazocineT40.491T40.492T40.493T40.494T40.495T40.496
PethidineT40.491T40.492T40.493T40.494T40.495T40.496
PhenazocineT40.491T40.492T40.493T40.494T40.495T40.496
ProfadolT40.491T40.492T40.493T40.494T40.495T40.496
PropoxypheneT40.491T40.492T40.493T40.494T40.495T40.496

Code History

  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - Code Added, effective from 10/1/2020 through 9/30/2021

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.