2026 ICD-10-CM Diagnosis Code T44.5X6AUnderdosing of predominantly beta-adrenoreceptor agonists, initial encounter

ICD-10-CM Codes›S00–T88›T36-T50›T44

ICD-10-CM T44.5X6A
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T44.5X6A is a billable ICD-10-CM diagnosis code for underdosing of predominantly beta-adrenoreceptor agonists, initial encounter. The 7th character A marks it as an initial encounter code, used while the patient is receiving active treatment. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). The code is not accepted as a principal diagnosis by the Medicare Code Editor. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Underdosing of drugs and medicaments, initial encounter.

Code Identity

ICD-10-CM Code
T44.5X6A
Billable Status
Yes — Valid for Submission
Code Describes
Underdosing of predominantly beta-adrenoreceptor agonists, initial encounter
Short Description
Underdosing of predominantly beta-adrenocpt agonists, init
Parent Code
T44.5X6
Underdosing of predominantly beta-adrenoreceptor agonists

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionT36-T50Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances
CategoryT44Poisoning by, adverse effect of and underdosing of drugs primarily affecting the autonomic nervous system
This CodeT44.5X6AUnderdosing of predominantly beta-adrenoreceptor agonists, initial encounter

Code EditsBilling

Medicare Code Editor checks that affect claim validity for T44.5X6A.

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.

Coding GuidelinesGuidance

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 drugs primarily affecting the autonomic nervous system (T44). Use the following options for the applicable episode of care:

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

Source: ICD-10-CM Official Guidelines for Coding and Reporting, FY 2026, published by CMS and the National Center for Health Statistics.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR INJ029
Underdosing of drugs and medicaments, initial encounter
Default principal diagnosis: inpatient No · outpatient No

Clinical InformationClinical

  • Beclomethasone

    an anti-inflammatory, synthetic glucocorticoid. it is used topically as an anti-inflammatory agent and in aerosol form for the treatment of asthma.

  • Budesonide

    a glucocorticoid used in the management of asthma, the treatment of various skin disorders, and allergic rhinitis.

  • Budesonide, Formoterol Fumarate Drug Combination

    a pharmaceutical preparation of budesonide and formoterol fumarate that is used as an anti-asthmatic agent and for the treatment of chronic obstructive pulmonary disease.

  • Dobutamine

    a catecholamine derivative with specificity for beta-1 adrenergic receptors. it is commonly used as a cardiotonic agent after cardiac surgery and during dobutamine stress echocardiography.

  • Echocardiography, Stress

    a method of recording heart motion and internal structures by combining ultrasonic imaging with exercise testing (exercise test) or pharmacologic stress.

  • Epinephrine

    the active sympathomimetic hormone from the adrenal medulla. it stimulates both the alpha- and beta- adrenergic systems, causes systemic vasoconstriction and gastrointestinal relaxation, stimulates the heart, and dilates bronchi and cerebral vessels. it is used in asthma and cardiac failure and to delay absorption of local anesthetics.

  • Racepinephrine

    a racemic mixture of d-epinephrine and l-epinephrine.

  • Receptors, Adrenergic

    cell-surface proteins that bind epinephrine and/or norepinephrine with high affinity and trigger intracellular changes. the two major classes of adrenergic receptors, alpha and beta, were originally discriminated based on their cellular actions but now are distinguished by their relative affinity for characteristic synthetic ligands. adrenergic receptors may also be classified according to the subtypes of g-proteins with which they bind; this scheme does not respect the alpha-beta distinction.

  • Isoetharine

    adrenergic beta-2 agonist used as bronchodilator for emphysema, bronchitis and asthma.

  • Prenalterol

    a partial adrenergic agonist with functional beta 1-receptor specificity and inotropic effect. it is effective in the treatment of acute cardiac failure, postmyocardial infarction low-output syndrome, shock, and reducing orthostatic hypotension in the shy-rager syndrome.

  • Procaterol

    a long-acting beta-2-adrenergic receptor agonist.

  • Ritodrine

    an adrenergic beta-2 agonist used to control premature labor.

  • Xamoterol

    a phenoxypropanolamine derivative that is a selective beta-1-adrenergic agonist.

Table of Drugs and ChemicalsClinical

Substances in the Table of Drugs and Chemicals that reference this code family. Always confirm in the Tabular List before coding.

SubstanceAccidentalSelf-harmAssaultUndeter­minedAdverse
Effect		Under­dosing
AdrenalineT44.5X1T44.5X2T44.5X3T44.5X4T44.5X5T44.5X6
AngiotensinT44.5X1T44.5X2T44.5X3T44.5X4T44.5X5T44.5X6
BeclomethasoneT44.5X1T44.5X2T44.5X3T44.5X4T44.5X5T44.5X6
BudesonideT44.5X1T44.5X2T44.5X3T44.5X4T44.5X5T44.5X6
DobutamineT44.5X1T44.5X2T44.5X3T44.5X4T44.5X5T44.5X6
EpinephrineT44.5X1T44.5X2T44.5X3T44.5X4T44.5X5T44.5X6
IsoetharineT44.5X1T44.5X2T44.5X3T44.5X4T44.5X5T44.5X6
PrenalterolT44.5X1T44.5X2T44.5X3T44.5X4T44.5X5T44.5X6
ProcaterolT44.5X1T44.5X2T44.5X3T44.5X4T44.5X5T44.5X6
RacepinefrinT44.5X1T44.5X2T44.5X3T44.5X4T44.5X5T44.5X6
RitodrineT44.5X1T44.5X2T44.5X3T44.5X4T44.5X5T44.5X6
XamoterolT44.5X1T44.5X2T44.5X3T44.5X4T44.5X5T44.5X6

Patient EducationClinical

Medication Errors

Medicines treat infectious diseases, prevent problems from chronic diseases, and ease pain. But medicines can also cause harmful reactions if not used correctly. Errors can happen in the hospital, at the health care provider's office, at the pharmacy, or at home. You can help prevent errors by:

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert T44.5X6A to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
No Map There is no ICD-9 equivalent for this code.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About T44.5X6AOverview

Is T44.5X6A (Underdosing of predominantly beta-adrenoreceptor agonists) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report underdosing of predominantly beta-adrenoreceptor agonists, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character A in T44.5X6A mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for underdosing of predominantly beta-adrenoreceptor agonists, such as an emergency visit or first evaluation.

Can T44.5X6A be a principal diagnosis?

No. The Medicare Code Editor rejects this code as a principal diagnosis because underdosing of predominantly beta-adrenoreceptor agonists, initial encounter describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.

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.