MCMedicalCodingSoftware
T43.506A

T43.506A: Underdosing of unspecified antipsychotics and neuroleptics, initial encounter

Billable / specific codeICD-10-CM

T43.506A is a billable, specific ICD-10-CM code for underdosing of unspecified antipsychotics and neuroleptics, initial encounter. It is valid for submission on a claim.

Check T43.506A with the rest of the claim: free scrubber

7th character "A": initial encounter

The appropriate 7th character is to be added to each code from category T43

A
initial encounter
D
subsequent encounter
S
sequela

Excludes1 inherited from the categories above T43.506A

A category’s note binds every code beneath it.

Written on T43.5: Poisoning by, adverse effect of and underdosing of other and unspecified antipsychotics and neuroleptics

  • poisoning by, adverse effect of and underdosing of rauwolfia (T46.5-)

Excludes2 inherited from the categories above T43.506A

Not part of this code, but both may be coded when both are present.

Written on T43: Poisoning by, adverse effect of and underdosing of psychotropic drugs, not elsewhere classified

  • appetite depressants (T50.5-)
  • barbiturates (T42.3-)
  • benzodiazepines (T42.4-)
  • drug dependence and related mental and behavioral disorders due to psychoactive substance use (F10.- -F19.-)
  • methaqualone (T42.6-)
  • psychodysleptics [hallucinogens] (T40.7-T40.9-)

Risk adjustment

No CMS-HCC V28 category: this code does not change a RAF score.

Medicare coverage

T43.506A is named in 2 Medicare coverage policies: 2 listing it as supporting medical necessity. Which one applies depends on your Medicare contractor.

  • A56612Billing and Coding: CT of the Head
  • A56645Billing and Coding: Controlled Substance Monitoring and Drugs of Abuse Testing

Code history

Unchanged in every release from FY2024 to FY2027.

Other codes under T43.506

ICD-10-CMFY2027· effective October 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release: see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.