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I1A.0

I1A.0Resistant hypertension

Billable / specific codeICD-10-CM

I1A.0 is a billable, specific ICD-10-CM code for resistant hypertension. It is valid for submission on a claim.

Code first

The underlying condition must be sequenced before this code.

  • specific type of existing hypertension, if known, such as:
  • essential hypertension (I10)
  • secondary hypertension (I15.-)

Inclusion terms

Alternative wordings a physician may use in the chart for this same code.

  • Apparent treatment resistant hypertension
  • Treatment resistant hypertension
  • True resistant hypertension

Risk adjustment

I1A.0 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

I1A.0 is named in 17 Medicare coverage policies 17 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

  • A53026Billing and Coding: Bariatric Surgery Coverage
  • A56422Billing and Coding: Bariatric Surgical Management of Morbid Obesity
  • A56605Billing and Coding: B-type Natriuretic Peptide (BNP) Testing
  • A56675Billing and Coding: Homocysteine Level, Serum

How I1A.0 is indexed

Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to I1A.0.

  • Hypertension, hypertensiveresistant(apparent treatment) (treatment) (true)

Questions about I1A.0

Is I1A.0 a billable ICD-10-CM code?
Yes. I1A.0 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does I1A.0 sit in the tabular list?
Diseases of the circulatory system (I00-I99), in the block Hypertensive diseases (I10-I1A).
ICD-10-CMFY2026-Apr· effective April 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.