M25.661 Stiffness of right knee, not elsewhere classified

Billable ICD-10-CM code, FY2026.

Applies from M25 Other joint disorder, not elsewhere classified

Excludes2 (not included here)

• abnormality of gait and mobility (R26.-)
• acquired deformities of limb (M20-M21)
• calcification of bursa (M71.4-)
• calcification of shoulder (joint) (M75.3)
• calcification of tendon (M65.2-)
• difficulty in walking (R26.2)
• temporomandibular joint disorder (M26.6-)

Applies from M25.6 Stiffness of joint, not elsewhere classified

Excludes1 (never code together)

• ankylosis of joint (M24.6-)
• contracture of joint (M24.5-)

MS-DRG index

Defines the logic of DRG(s) 555-556 in MDC 08.

Approximate ICD-9-CM (GEMs)

• 719.56 Stiffness of joint, not elsewhere classified, lower leg (approximate)

Code annotations containing back-references to M25.661

Back-references to M25.6

• Type 1 Excludes: M24.6 Ankylosis of joint ("stiffness of joint without ankylosis (M25.6-)")

Nearby codes

• M25.65 Stiffness of hip, not elsewhere classified
• M25.651 Stiffness of right hip, not elsewhere classified
• M25.652 Stiffness of left hip, not elsewhere classified
• M25.659 Stiffness of unspecified hip, not elsewhere classified
• M25.66 Stiffness of knee, not elsewhere classified
• M25.661 Stiffness of right knee, not elsewhere classified (this code)
• M25.662 Stiffness of left knee, not elsewhere classified
• M25.669 Stiffness of unspecified knee, not elsewhere classified
• M25.67 Stiffness of ankle and foot, not elsewhere classified
• M25.671 Stiffness of right ankle, not elsewhere classified
• M25.672 Stiffness of left ankle, not elsewhere classified