E70.9Disorder of aromatic amino-acid metabolism, unspecified

E70.9 is the ICD-10-CM diagnosis code for disorder of aromatic amino-acid metabolism, unspecified. It belongs to category E70 (disorders of aromatic amino-acid metabolism), block E70-E88 (metabolic disorders) and chapter 4 (endocrine, nutritional and metabolic diseases). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within E70, choose E70.9 (Disorder of aromatic amino-acid metabolism, unspecified) only when documentation doesn't support a more specific option: classical phenylketonuria (E70.0), other hyperphenylalaninemias (E70.1), disorders of tyrosine metabolism (E70.2), albinism (E70.3), disorders of histidine metabolism (E70.4), disorders of tryptophan metabolism (E70.5) and other disorders of aromatic amino-acid metabolism (E70.8).

As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.

In MS-DRG v44.0, it is part of the grouping logic for DRG 642 (Inborn and Other Disorders of Metabolism, relative weight 1.3219), in MDC 10 (Endocrine, Nutritional and Metabolic Diseases and Disorders), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 270.2 (other disturbances of aromatic amino-acid metabolism).