MS-DRG · FY 2026 v43.0
MS-DRG 642 – Inborn and Other Disorders of Metabolism
A Medical DRG in MDC 10 (Endocrine, Nutritional & Metabolic Diseases & Disorders). Inpatient cases group to DRG 642 when the ICD-10-CM principal diagnosis is one of the 216 codes listed below. Its FY 2026 relative weight is 1.4221 with a geometric mean length of stay of 3.4 days.
Medical DRG – assigned by principal diagnosis✓ Official CMS v43.0 dataset
1.4221
Relative Weight
3.4
Geometric Mean LOS (days)
4.6
Arithmetic Mean LOS (days)
216
Principal Diagnosis Codes
How a case is assigned to DRG 642
The grouper first assigns the case to MDC 10 from the principal diagnosis and finds no qualifying operating-room procedure (this is a Medical DRG; ICD-10-PCS codes do not drive assignment here).
ICD-10-CM
Principal Diagnosis Codes 216 codes · 16 categories
216 of 216 shown
C96 Other and unspecified malignant neoplasms of lymphoid, hematopoietic and related tissue2 codes
D81 Combined immunodeficiencies6 codes
D84 Other immunodeficiencies1 code
- D84.1 Defects in the complement system
E70 Disorders of aromatic amino-acid metabolism26 codes
- E70.0 Classical phenylketonuria
- E70.1 Other hyperphenylalaninemias
- E70.20 Disorder of tyrosine metabolism, unspecified
- E70.21 Tyrosinemia
- E70.29 Other disorders of tyrosine metabolism
- E70.30 Albinism, unspecified
- E70.310 X-linked ocular albinism
- E70.311 Autosomal recessive ocular albinism
- E70.318 Other ocular albinism
- E70.319 Ocular albinism, unspecified
- E70.320 Tyrosinase negative oculocutaneous albinism
- E70.321 Tyrosinase positive oculocutaneous albinism
- E70.328 Other oculocutaneous albinism
- E70.329 Oculocutaneous albinism, unspecified
- E70.330 Chediak-Higashi syndrome
- E70.331 Hermansky-Pudlak syndrome
- E70.338 Other albinism with hematologic abnormality
- E70.339 Albinism with hematologic abnormality, unspecified
- E70.39 Other specified albinism
- E70.40 Disorders of histidine metabolism, unspecified
- E70.41 Histidinemia
- E70.49 Other disorders of histidine metabolism
- E70.5 Disorders of tryptophan metabolism
- E70.81 Aromatic L-amino acid decarboxylase deficiency
- E70.89 Other disorders of aromatic amino-acid metabolism
- E70.9 Disorder of aromatic amino-acid metabolism, unspecified
E71 Disorders of branched-chain amino-acid metabolism and fatty-acid metabolism38 codes
- E71.0 Maple-syrup-urine disease
- E71.110 Isovaleric acidemia
- E71.111 3-methylglutaconic aciduria
- E71.118 Other branched-chain organic acidurias
- E71.120 Methylmalonic acidemia
- E71.121 Propionic acidemia
- E71.128 Other disorders of propionate metabolism
- E71.19 Other disorders of branched-chain amino-acid metabolism
- E71.2 Disorder of branched-chain amino-acid metabolism, unspecified
- E71.30 Disorder of fatty-acid metabolism, unspecified
- E71.310 Long chain/very long chain acyl CoA dehydrogenase deficiency
- E71.311 Medium chain acyl CoA dehydrogenase deficiency
- E71.312 Short chain acyl CoA dehydrogenase deficiency
- E71.313 Glutaric aciduria type II
- E71.314 Muscle carnitine palmitoyltransferase deficiency
- E71.318 Other disorders of fatty-acid oxidation
- E71.32 Disorders of ketone metabolism
- E71.39 Other disorders of fatty-acid metabolism
- E71.40 Disorder of carnitine metabolism, unspecified
- E71.41 Primary carnitine deficiency
- E71.42 Carnitine deficiency due to inborn errors of metabolism
- E71.43 Iatrogenic carnitine deficiency
- E71.440 Ruvalcaba-Myhre-Smith syndrome
- E71.448 Other secondary carnitine deficiency
- E71.50 Peroxisomal disorder, unspecified
- E71.510 Zellweger syndrome
- E71.511 Neonatal adrenoleukodystrophy
- E71.518 Other disorders of peroxisome biogenesis
- E71.520 Childhood cerebral X-linked adrenoleukodystrophy
- E71.521 Adolescent X-linked adrenoleukodystrophy
- E71.522 Adrenomyeloneuropathy
- E71.528 Other X-linked adrenoleukodystrophy
- E71.529 X-linked adrenoleukodystrophy, unspecified type
- E71.53 Other group 2 peroxisomal disorders
- E71.540 Rhizomelic chondrodysplasia punctata
- E71.541 Zellweger-like syndrome
- E71.542 Other group 3 peroxisomal disorders
- E71.548 Other peroxisomal disorders
E72 Other disorders of amino-acid metabolism27 codes
- E72.00 Disorders of amino-acid transport, unspecified
- E72.01 Cystinuria
- E72.02 Hartnup's disease
- E72.03 Lowe's syndrome
- E72.04 Cystinosis
- E72.09 Other disorders of amino-acid transport
- E72.10 Disorders of sulfur-bearing amino-acid metabolism, unspecified
- E72.11 Homocystinuria
- E72.12 Methylenetetrahydrofolate reductase deficiency
- E72.19 Other disorders of sulfur-bearing amino-acid metabolism
- E72.20 Disorder of urea cycle metabolism, unspecified
- E72.21 Argininemia
- E72.22 Arginosuccinic aciduria
- E72.23 Citrullinemia
- E72.29 Other disorders of urea cycle metabolism
- E72.3 Disorders of lysine and hydroxylysine metabolism
- E72.4 Disorders of ornithine metabolism
- E72.50 Disorder of glycine metabolism, unspecified
- E72.51 Non-ketotic hyperglycinemia
- E72.52 Trimethylaminuria
- E72.530 Primary hyperoxaluria, type 1
- E72.538 Other specified primary hyperoxaluria
- E72.539 Primary hyperoxaluria, unspecified
- E72.59 Other disorders of glycine metabolism
- E72.81 Disorders of gamma aminobutyric acid metabolism
- E72.89 Other specified disorders of amino-acid metabolism
- E72.9 Disorder of amino-acid metabolism, unspecified
E74 Other disorders of carbohydrate metabolism18 codes
- E74.00 Glycogen storage disease, unspecified
- E74.01 von Gierke disease
- E74.02 Pompe disease
- E74.03 Cori disease
- E74.04 McArdle disease
- E74.05 Lysosome-associated membrane protein 2 [LAMP2] deficiency
- E74.09 Other glycogen storage disease
- E74.20 Disorders of galactose metabolism, unspecified
- E74.21 Galactosemia
- E74.29 Other disorders of galactose metabolism
- E74.4 Disorders of pyruvate metabolism and gluconeogenesis
- E74.810 Glucose transporter protein type 1 deficiency
- E74.818 Other disorders of glucose transport
- E74.819 Disorders of glucose transport, unspecified
- E74.820 SLC13A5 Citrate Transporter Disorder
- E74.829 Other disorders of citrate metabolism
- E74.89 Other specified disorders of carbohydrate metabolism
- E74.9 Disorder of carbohydrate metabolism, unspecified
E75 Disorders of sphingolipid metabolism and other lipid storage disorders12 codes
- E75.21 Fabry (-Anderson) disease
- E75.22 Gaucher disease
- E75.240 Niemann-Pick disease type A
- E75.241 Niemann-Pick disease type B
- E75.242 Niemann-Pick disease type C
- E75.243 Niemann-Pick disease type D
- E75.244 Niemann-Pick disease type A/B
- E75.248 Other Niemann-Pick disease
- E75.249 Niemann-Pick disease, unspecified
- E75.3 Sphingolipidosis, unspecified
- E75.5 Other lipid storage disorders
- E75.6 Lipid storage disorder, unspecified
E76 Disorders of glycosaminoglycan metabolism12 codes
- E76.01 Hurler's syndrome
- E76.02 Hurler-Scheie syndrome
- E76.03 Scheie's syndrome
- E76.1 Mucopolysaccharidosis, type II
- E76.210 Morquio A mucopolysaccharidoses
- E76.211 Morquio B mucopolysaccharidoses
- E76.219 Morquio mucopolysaccharidoses, unspecified
- E76.22 Sanfilippo mucopolysaccharidoses
- E76.29 Other mucopolysaccharidoses
- E76.3 Mucopolysaccharidosis, unspecified
- E76.8 Other disorders of glucosaminoglycan metabolism
- E76.9 Glucosaminoglycan metabolism disorder, unspecified
E77 Disorders of glycoprotein metabolism4 codes
E78 Disorders of lipoprotein metabolism and other lipidemias16 codes
- E78.00 Pure hypercholesterolemia, unspecified
- E78.010 Homozygous familial hypercholesterolemia [HoFH]
- E78.011 Heterozygous familial hypercholesterolemia [HeFH]
- E78.019 Familial hypercholesterolemia, unspecified
- E78.1 Pure hyperglyceridemia
- E78.2 Mixed hyperlipidemia
- E78.3 Hyperchylomicronemia
- E78.41 Elevated Lipoprotein(a)
- E78.49 Other hyperlipidemia
- E78.5 Hyperlipidemia, unspecified
- E78.6 Lipoprotein deficiency
- E78.70 Disorder of bile acid and cholesterol metabolism, unspecified
- E78.79 Other disorders of bile acid and cholesterol metabolism
- E78.81 Lipoid dermatoarthritis
- E78.89 Other lipoprotein metabolism disorders
- E78.9 Disorder of lipoprotein metabolism, unspecified
E79 Disorders of purine and pyrimidine metabolism6 codes
E80 Disorders of porphyrin and bilirubin metabolism6 codes
E83 Disorders of mineral metabolism17 codes
- E83.00 Disorder of copper metabolism, unspecified
- E83.01 Wilson's disease
- E83.09 Other disorders of copper metabolism
- E83.10 Disorder of iron metabolism, unspecified
- E83.110 Hereditary hemochromatosis
- E83.111 Hemochromatosis due to repeated red blood cell transfusions
- E83.118 Other hemochromatosis
- E83.119 Hemochromatosis, unspecified
- E83.19 Other disorders of iron metabolism
- E83.30 Disorder of phosphorus metabolism, unspecified
- E83.31 Familial hypophosphatemia
- E83.32 Hereditary vitamin D-dependent rickets (type 1) (type 2)
- E83.39 Other disorders of phosphorus metabolism
- E83.822 ENPP1 deficiency causing autosomal recessive hypophosphatemic rickets type 2
- E83.824 ABCC6 deficiency causing pseudoxanthoma elasticum
- E83.89 Other disorders of mineral metabolism
- E83.9 Disorder of mineral metabolism, unspecified
E88 Other and unspecified metabolic disorders21 codes
- E88.01 Alpha-1-antitrypsin deficiency
- E88.10 Lipodystrophy, unspecified
- E88.11 Partial lipodystrophy
- E88.12 Generalized lipodystrophy
- E88.13 Localized lipodystrophy
- E88.14 HIV-associated lipodystrophy
- E88.19 Other lipodystrophy, not elsewhere classified
- E88.2 Lipomatosis, not elsewhere classified
- E88.40 Mitochondrial metabolism disorder, unspecified
- E88.41 MELAS syndrome
- E88.42 MERRF syndrome
- E88.43 Disorders of mitochondrial tRNA synthetases
- E88.49 Other mitochondrial metabolism disorders
- E88.810 Metabolic syndrome
- E88.811 Insulin resistance syndrome, Type A
- E88.818 Other insulin resistance
- E88.819 Insulin resistance, unspecified
- E88.82 Obesity due to disruption of MC4R pathway
- E88.89 Other specified metabolic disorders
- E88.9 Metabolic disorder, unspecified
- E88.A Wasting disease (syndrome) due to underlying condition
ICD-10-PCS
Procedure Codes
Procedure codes do not drive assignment for this DRG. DRG 642 is a Medical DRG, assigned from the principal diagnosis above.
Frequently Asked Questions
What is MS-DRG 642?
MS-DRG 642 (Inborn and Other Disorders of Metabolism) is a medical DRG in MDC 10 (Endocrine, Nutritional & Metabolic Diseases & Disorders). Its FY 2026 relative weight is 1.4221 with a geometric mean length of stay of 3.4 days.
How many diagnosis codes group to DRG 642?
216 ICD-10-CM principal diagnosis codes group to this DRG, spanning 16 three-character categories.
What is the relative weight of DRG 642?
The FY 2026 relative weight of this DRG is 1.4221, meaning reimbursement of roughly 1.42 times the average Medicare inpatient case. Multiply by a hospital's blended base rate for the approximate payment.
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Source: CMS ICD-10 MS-DRG v43.0 Definitions Manual and the FY 2026 IPPS Final Rule (Table 5), effective October 1, 2025 through September 30, 2026. We publish the DRG assignments as CMS defines them and add the navigation, search, and code links.
