MCMCB Pro
R78.89

R78.89Finding of other specified substances, not normally found in blood

Billable / specific codeICD-10-CM

R78.89 is a billable, specific ICD-10-CM code for finding of other specified substances, not normally found in blood. It is valid for submission on a claim.

Inclusion terms

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

  • Finding of abnormal level of lithium in blood

Other codes that can never be billed with R78.89

These codes carry an Excludes1 note pointing at R78.89. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading R78.89 alone.

  • R79.0Abnormal level of blood mineral

Risk adjustment

R78.89 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

R78.89 is named in 4 Medicare coverage policies 4 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

  • A56686Billing and Coding: HbA1c
  • A57063Billing and Coding: Diagnostic and Therapeutic Esophagogastroduodenoscopy
  • A57189Billing and Coding: Serum Magnesium
  • A59186Billing and Coding: Magnesium

How R78.89 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 R78.89.

  • Abnormal, abnormality, abnormalitiesblood levellithium
  • Findings, abnormal, inconclusive, without diagnosisin bloodlithium(abnormal level)
  • Findings, abnormal, inconclusive, without diagnosisin bloodspecified substance NEC

Related codes at this level

Codes that share R78.8. If R78.89 is not quite right, the correct code is usually one of these.

Questions about R78.89

Is R78.89 a billable ICD-10-CM code?
Yes. R78.89 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does R78.89 sit in the tabular list?
Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99), in the block Abnormal findings on examination of blood, without diagnosis (R70-R79).
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.