M1A.4791 — Other secondary chronic gout, unspecified ankle and foot, with tophus (tophi)
M1A.4791 is a billable, specific ICD-10-CM code for other secondary chronic gout, unspecified ankle and foot, with tophus (tophi). It is valid for submission on a claim.
7th character "1" — with tophus (tophi)
The appropriate 7th character is to be added to each code from category M1A
- 0
- without tophus (tophi)
- 1
- with tophus (tophi)
Excludes1 inherited from the categories above M1A.4791
These are not written on M1A.4791, but they bind it: a note on a category applies to every code beneath it. Billing M1A.4791 with anything listed here is a denial.
Excludes2 inherited from the categories above M1A.4791
Also inherited, and the opposite of Excludes1: these conditions are not part of M1A.4791, but a patient can have both, so you may code both.
Other codes that can never be billed with M1A.4791
These codes carry an Excludes1 note pointing at M1A.4791. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading M1A.4791 alone.
Risk adjustment
M1A.4791 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
M1A.4791 is named in 7 Medicare coverage policies — 0 listing it as supporting medical necessity, and 7 listing it as NOT covered. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.
- A58865Billing and Coding: Amniotic and Placental-Derived Product Injections and/or Applications for Musculoskeletal Indications, Non-Woundnot covered
- A58883Billing and Coding: Amniotic and Placental-Derived Product Injections and/or Applications for Musculoskeletal Indications, Non-Woundnot covered
- A58893Billing and Coding: Amniotic and Placental-Derived Product Injections and/or Applications for Musculoskeletal Indications, Non-Woundnot covered
- A59374Billing and Coding: Amniotic and Placental-Derived Product Injections and/or Applications for Musculoskeletal Indications, Non-Woundnot covered
Code history
M1A.4791 has not changed since FY2024 — no addition, revision or deletion across the three most recent ICD-10-CM releases.
Related codes at this level
Codes that share M1A.479. If M1A.4791 is not quite right, the correct code is usually one of these.
Questions about M1A.4791
- Is M1A.4791 a billable ICD-10-CM code?
- Yes. M1A.4791 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
- Where does M1A.4791 sit in the tabular list?
- Diseases of the musculoskeletal system and connective tissue (M00-M99), in the block Inflammatory polyarthropathies (M05-M14).
- What cannot be coded together with M1A.4791?
- M1A.4791 carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above M1A.4791 (M1A) and apply to it just the same.