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ICD-10-CM tabular list

Q20-Q28Congenital malformations of the circulatory system

ICD-10-CM codes Q20-Q28 cover congenital malformations of the circulatory system, within congenital malformations, deformations and chromosomal abnormalities. The block holds 118 codes across 9 categories, of which 102 are billable and 16 are header codes that cannot be submitted on a claim.

What else to watch in Q20-Q28

  • 6 codes are laterality-specific. They come in left and right pairs, and the pair is mutually exclusive on a single site: coding both without a bilateral code is a contradiction a scrubber should catch before the payer does.
  • 102 codes are named in Medicare coverage policies. An LCD or NCD lists them as supporting medical necessity, or explicitly as not supporting it. Which applies depends on the MAC for your state.

Categories in Q20-Q28

ICD-10-CMFY2026-Apr· effective April 1, 2026