2026 ICD-10-CM Diagnosis Code T47.8X6AUnderdosing of other agents primarily affecting gastrointestinal system, initial encounter
T47.8X6A is a billable ICD-10-CM diagnosis code for underdosing of other agents primarily affecting gastrointestinal system, 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
Code Classification
Code EditsBilling
Medicare Code Editor checks that affect claim validity for T47.8X6A.
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 agents primarily affecting the gastrointestinal system (T47). 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.
Clinical InformationClinical
Actinobacillus equuli
a genus of gram-negative bacteria in the genus actinobacillus, which is pathogenic for horses and pigs.Aeromonas caviae
a species of gram-negative, facultatively anaerobic bacteria that is found in domestic and wild animals including birds, and fish. in humans it causes gastroenteritis in young children and some adults.Agrobacterium tumefaciens
a species of gram-negative, aerobic bacteria isolated from soil and the stems, leafs, and roots of plants. some biotypes are pathogenic and cause the formation of plant tumors in a wide variety of higher plants. the species is a major research tool in biotechnology.Aliivibrio fischeri
a species of gram-negative bacteria in the genus aliivibrio, which exhibits luminescence. a. fischeri is found in a symbiotic relationship with the squid euprymna scolopes.Anthrax
an acute infection caused by the spore-forming bacteria bacillus anthracis. it commonly affects hoofed animals such as sheep and goats. infection in humans often involves the skin (cutaneous anthrax), the lungs (inhalation anthrax), or the gastrointestinal tract. anthrax is not contagious and can be treated with antibiotics.Bacillus
a genus of bacillaceae that are spore-forming, rod-shaped cells. most species are saprophytic soil forms with only a few species being pathogenic.Bacillus amyloliquefaciens
a non-pathogenic species of bacillus that occurs in soil as well as some fermented vegetables and fermented dairy products. it produces bacteriocins and antifungal agents and is used in food preservation as well as a probiotic.Bacillus anthracis
a species of bacteria that causes anthrax in humans and animals.Bacillus cereus
a species of rod-shaped bacteria that is a common soil saprophyte. its spores are widespread and multiplication has been observed chiefly in foods. contamination may lead to food poisoning.Bacillus clausii
an alkalophilic species of bacillus that occurs in soil. it produces anti-bacterial agents and is used as a probiotic.Bacillus coagulans
a microaerophilic, lactic acid producing species of bacillus that occurs in fermented foods. it also produces anti-infective agents and is used as a probiotic.Bacillus firmus
a species of bacillus that occurs in soil and marine sediments. many strains are alkalophilic and able to metabolize heavy metals; it may therefore be a useful species for environmental biodegradation.Bacillus licheniformis
a species of bacillus that occurs in soil and is frequently found on bird feathers. some strains cause foodborne disease, whereas other strains produce antifungal agents and antibacterial agents and function as probiotics. this species can also produce enzymes for industrial applications.Bacillus megaterium
a species of bacteria whose spores vary from round to elongate. it is a common soil saprophyte.Bacillus Phages
viruses whose host is bacillus. frequently encountered bacillus phages include bacteriophage phi 29 and bacteriophage phi 105.Bacillus pumilus
a species of bacillus that occurs in soil, especially around the roots of some plants where it has anti-fungal and anti-nematode activities. it can also produce enzymes for industrial applications.Bacillus subtilis
a species of gram-positive bacteria that is a common soil and water saprophyte.Bacillus thuringiensis
a species of gram-positive bacteria which may be pathogenic for certain insects. it is used for the biological control of the gypsy moth.Bacillus thuringiensis Toxins
endotoxins produced by bacillus thuringiensis used in transgenic plants and insecticides. when eaten by a susceptible insect they are protease activated in the insect midgut resulting in death from bacterial septicemia.BCG Vaccine
an active immunizing agent and a viable avirulent attenuated strain of mycobacterium bovis, which confers immunity to mycobacterial infections. it is used also in immunotherapy of neoplasms due to its stimulation of antibodies and non-specific immunity.Bordetella bronchiseptica
a species of bordetella that is parasitic and pathogenic. it is found in the respiratory tract of domestic and wild mammalian animals and can be transmitted from animals to man. it is a common cause of bronchopneumonia in lower animals.Erwinia amylovora
a species of gram-negative bacteria, in the genus erwinia, causing a necrotic disease of plants.Escherichia coli
a species of gram-negative, facultatively anaerobic, rod-shaped bacteria (gram-negative facultatively anaerobic rods) commonly found in the lower part of the intestine of warm-blooded animals. it is usually nonpathogenic, but some strains are known to produce diarrhea and pyogenic infections. pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (enterotoxigenic escherichia coli), etc.Geobacillus stearothermophilus
a species of gram-positive endospore-forming bacteria in the family bacillaceae, found in soil, hot springs, arctic waters, ocean sediments, and spoiled food products.Haemophilus ducreyi
a species of haemophilus that appears to be the pathogen or causative agent of the sexually transmitted disease, chancroid.Klebsiella oxytoca
a species of gram-negative bacteria causing urinary tract infections and septicemia.Klebsiella pneumoniae
gram-negative, non-motile, capsulated, gas-producing rods found widely in nature and associated with urinary and respiratory infections in humans.Morganella morganii
a species of morganella formerly classified as a proteus species. it is found in the feces of humans, dogs, other mammals, and reptiles. (from bergey's manual of determinative bacteriology, 9th ed)Paenibacillus polymyxa
a species of paenibacillus formerly classified as bacillus polymyxa that occurs in marine sediments and soil, especially around plant roots and rhizomes where it performs nitrogen fixation. it has activity against several species of pathogenic bacteria and produces polymyxins.Pectobacterium carotovorum
a species of gram-negative, facultatively anaerobic, rod-shaped bacteria that causes rotting, particularly of storage tissues, of a wide variety of plants and causes a vascular disease in carrots; and potato plants.Pseudomonas aeruginosa
a species of gram-negative, aerobic, rod-shaped bacteria commonly isolated from clinical specimens (wound, burn, and urinary tract infections). it is also found widely distributed in soil and water. p. aeruginosa is a major agent of nosocomial infection.Pseudomonas fluorescens
a species of nonpathogenic fluorescent bacteria found in feces, sewage, soil, and water, and which liquefy gelatin.Pseudomonas stutzeri
a species of gram-negative bacteria in the genus pseudomonas, containing multiple genomovars. it is distinguishable from other pseudomonad species by its ability to use maltose and starch as sole carbon and energy sources. it can degrade environmental pollutants and has been used as a model organism to study denitrification.Shigella dysenteriae
a species of gram-negative, facultatively anaerobic, rod-shaped bacteria that is extremely pathogenic and causes severe dysentery. infection with this organism often leads to ulceration of the intestinal epithelium.Subtilisins
a family of serine endopeptidases isolated from bacillus subtilis. ec 3.4.21.-Vibrio cholerae
the etiologic agent of cholera.Xanthomonas campestris
a species of gram-negative, aerobic bacteria that is pathogenic for plants.Yersinia pestis
the etiologic agent of plague in man, rats, ground squirrels, and other rodents.Carrageenan
a water-soluble extractive mixture of sulfated polysaccharides from red algae. chief sources are the irish moss chondrus crispus (carrageen), and gigartina stellata. it is used as a stabilizer, for suspending cocoa in chocolate manufacture, and to clarify beverages.Cisapride
a substituted benzamide used for its prokinetic properties. it is used in the management of gastroesophageal reflux disease, functional dyspepsia, and other disorders associated with impaired gastrointestinal motility. (martindale the extra pharmacopoeia, 31st ed)
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.
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 T47.8X6A to ICD-9-CMHistory
Code HistoryHistory
Questions About T47.8X6AOverview
Is T47.8X6A a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report underdosing of other agents primarily affecting gastrointestinal system, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in T47.8X6A mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for underdosing of other agents primarily affecting gastrointestinal system, such as an emergency visit or first evaluation.
Can T47.8X6A be a principal diagnosis?
No. The Medicare Code Editor rejects this code as a principal diagnosis because underdosing of other agents primarily affecting gastrointestinal system, 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.
