T37.1X6A — Underdosing of antimycobacterial drugs, initial encounter
T37.1X6A is a billable, specific ICD-10-CM code for underdosing of antimycobacterial drugs, initial encounter. It is valid for submission on a claim.
7th character "A" — initial encounter
The appropriate 7th character is to be added to each code from category T37
- A
- initial encounter
- D
- subsequent encounter
- S
- sequela
Excludes1 inherited from the categories above T37.1X6A
These are not written on T37.1X6A, but they bind it: a note on a category applies to every code beneath it. Billing T37.1X6A with anything listed here is a denial.
Written on T37.1 — Poisoning by, adverse effect of and underdosing of antimycobacterial drugs
Risk adjustment
T37.1X6A does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.
Medicare coverage
T37.1X6A is named in 2 Medicare coverage policies — 2 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.
- A57473Billing and Coding: Allergy Testing
- A57473Billing and Coding: Allergy Testing
Code history
T37.1X6A has not changed since FY2024 — no addition, revision or deletion across the three most recent ICD-10-CM releases.
Related codes at this level
Codes that share T37.1X6. If T37.1X6A is not quite right, the correct code is usually one of these.
Questions about T37.1X6A
- Is T37.1X6A a billable ICD-10-CM code?
- Yes. T37.1X6A is a billable, specific ICD-10-CM code and is valid for submission on a claim.
- Where does T37.1X6A sit in the tabular list?
- Injury, poisoning and certain other consequences of external causes (S00-T88), in the block Poisoning by, adverse effects of and underdosing of drugs, medicaments and biological substances (T36-T50).
- What cannot be coded together with T37.1X6A?
- T37.1X6A carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above T37.1X6A (T37.1, T37) and apply to it just the same.