2026 ICD-10-CM Diagnosis Code M1A.9XX1Chronic gout, unspecified, with tophus (tophi)
ICD-10-CM Codes›M00–M99›M05-M14›M1A
- Billable — Valid for Submission
- 7th Character 1 — With Tophus
- Chronic Condition
M1A.9XX1 is a billable ICD-10-CM diagnosis code for chronic gout, unspecified, with tophus (tophi). The 7th character 1 reports chronic gout with tophus formation (tophi). It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 553 through 554. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Gout.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Bilateral chronic tophaceous gout of elbows
- Bilateral chronic tophaceous gout of hands
- Blood urate above reference range
- Blood urate outside reference range
- Chronic tophaceous gout of bilateral feet
- Chronic tophaceous gout of digit
- Chronic tophaceous gout of hand
- Chronic tophaceous gout of left elbow
- Chronic tophaceous gout of left foot
- Chronic tophaceous gout of left hand
- Chronic tophaceous gout of right elbow
- Chronic tophaceous gout of right foot
- Chronic tophaceous gout of right hand
- Chronic tophaceous gout of toe
- Gouty bursitis of knee
- Gouty bursitis of olecranon
- Gouty tophus
- Gouty tophus of bilateral ears
- Gouty tophus of bilateral olecranon bursae
- Gouty tophus of bursa
- Gouty tophus of heart
- Gouty tophus of left ear
- Gouty tophus of olecranon bursa
- Gouty tophus of pinna
- Gouty tophus of prepatellar bursa
- Gouty tophus of right ear
- Gouty tophus of tendon
- Hyperuricemia
- Prepatellar bursitis
- Visceral gout
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Hyperuricemia
excessive uric acid or urate in blood as defined by its solubility in plasma at 37 degrees c; greater than 0.42mmol per liter (7.0mg/dl) in men or 0.36mmol per liter (6.0mg/dl) in women. this condition is caused by overproduction of uric acid or impaired renal clearance. hyperuricemia can be acquired, drug-induced or genetically determined (lesch-nyhan syndrome). it is associated with hypertension and gout.Lesch-Nyhan Syndrome
an inherited disorder transmitted as a sex-linked trait and caused by a deficiency of an enzyme of purine metabolism; hypoxanthine phosphoribosyltransferase. affected individuals are normal in the first year of life and then develop psychomotor retardation, extrapyramidal movement disorders, progressive spasticity, and seizures. self-destructive behaviors such as biting of fingers and lips are seen frequently. intellectual impairment may also occur but is typically not severe. elevation of uric acid in the serum leads to the development of renal calculi and gouty arthritis. (menkes, textbook of child neurology, 5th ed, pp127)Hypoxanthine Phosphoribosyltransferase
an enzyme that catalyzes the conversion of 5-phosphoribosyl-1-pyrophosphate and hypoxanthine, guanine, or mercaptopurine to the corresponding 5'-mononucleotides and pyrophosphate. the enzyme is important in purine biosynthesis as well as central nervous system functions. complete lack of enzyme activity is associated with the lesch-nyhan syndrome, while partial deficiency results in overproduction of uric acid. ec 2.4.2.8.
Patient EducationClinical
Gout
Gout is a common type of inflammatory arthritis. It causes pain, swelling, and redness in one or more joints. It usually happens as a flare, which can last for a week or two and then gets better. The flares often begin in your big toe or a lower limb.
The full article covers:
- What is gout?
- What causes gout?
- Who is more likely to develop gout?
- What are the symptoms of gout?
- How is gout diagnosed?
- What are the treatments for gout?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert M1A.9XX1 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About M1A.9XX1Overview
Is M1A.9XX1 (Chronic gout, unspecified) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report chronic gout, unspecified, with tophus (tophi) on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character 1 in M1A.9XX1 mean?
The final character 1 reports chronic gout with tophus formation (tophi), in this case involving the chronic gout, unspecified.
What MS-DRG does M1A.9XX1 group to?
When chronic gout, unspecified, with tophus (tophi) is the principal diagnosis on an inpatient stay, it groups to MS-DRG 553, 554, with relative weights from 0.8301 to 1.2963 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of M1A.9XX1?
Under the General Equivalence Mappings, chronic gout, unspecified, with tophus (tophi) converts to ICD-9-CM 274.03 (chr gouty atroph w tophi). The mapping is approximate, so confirm the match fits the documentation.
Footnotes
[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:
- The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
- The condition places limitations on self-care, independent living, and social interactions.
