A52.78 ICD-10-CM Code: Syphilis of other musculoskeletal tissue
HCC Buddy Code Card
Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.
FY 2026 Apr update / Certain infectious and parasitic diseases (A00-B99) / Infections with a predominantly sexual mode of transmission (A50-A64)
A52.78
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceSyphilis of other musculoskeletal tissue
This code describes syphilis infection that affects bones, joints, muscles, or other structural tissues in the body, excluding the spine. This is a late-stage manifestation of untreated syphilis that causes inflammation and damage to these tissues.
CMS-HCC V28
00
RAF 0
CMS-HCC V24
00
RAF 0
ACA/HHS
00
RAF 0
ESRD/PACE
00
RAF 0
RXHCC
00
RAF 0
Code Trumping
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Code Book Path
Inclusion Terms
Official- Late syphilitic bursitis
- Syphilis [stage unspecified] of bursa
- Syphilis [stage unspecified] of muscle
- Syphilis [stage unspecified] of synovium
- Syphilis [stage unspecified] of tendon
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for A52.78 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for A52.78 in this effective period.
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for A52.78 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for A52.78 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for A52.78 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for A52.78 in this effective period.
Buddy Documentation Tip
Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.
Is A52.78 an HCC code?
No. A52.78 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.
This code does not map to an HCC category in any model (V28, V24, ESRD, RxHCC).
What This Code Means
A52.78 is the ICD-10-CM diagnosis code for syphilis of other musculoskeletal tissue. This code describes syphilis infection that affects bones, joints, muscles, or other structural tissues in the body, excluding the spine. This is a late-stage manifestation of untreated syphilis that causes inflammation and damage to these tissues. A52.78 sits in the ICD-10-CM chapter for certain infectious and parasitic diseases (a00-b99), within the section covering infections with a predominantly sexual mode of transmission (a50-a64).
A52.78 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.
Verify the specific musculoskeletal site affected and confirm this is tertiary syphilis; if spinal involvement is documented, use A52.77 instead.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for A52.78 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Verify the specific musculoskeletal site affected and confirm this is tertiary syphilis; if spinal involvement is documented, use A52.77 instead
- •Ensure documentation supports late syphilis diagnosis and that the condition is not better described by other A52.7x codes for neurosyphilis or cardiovascular syphilis