DxCodebookFY2027 · Oct 1, 2026 – Sep 30, 2027

Category · FY2027

K51 Ulcerative colitis

  • Header · not billable

K51 is not billable. The category heads 49 billable codes in FY2027, grouped under 7 subdivisions.

Index → code

  • Ileocolitisulcerative → K51.0-
  • Proctitisulcerative (chronic) → K51.20
  • Pancolitisulcerative (chronic) → K51.00

Where it sits

  1. Chapter 11 Diseases of the digestive system (K00-K95)
  2. K50-K52 Noninfective enteritis and colitis (K50-K52)
  3. K51 Ulcerative colitis
Billable codes
49
Subdivisions
7
CC / MCC codes
49 / 0
HCC V28 codes
49
New FY2027
0
Index entries
52

Codes in K51

  1. K51.0
    Ulcerative (chronic) pancolitis
    Header
    Inclusion terms 1

    Inclusion terms

    • Backwash ileitis
  2. K51.00
    Ulcerative (chronic) pancolitis without complications
    BillableCC81
    Inclusion terms 1

    Inclusion terms

    • Ulcerative (chronic) pancolitis NOS
  3. K51.01
    Ulcerative (chronic) pancolitis with complications
    Header
  4. K51.011
    Ulcerative (chronic) pancolitis with rectal bleeding
    BillableCC81
  5. K51.012
    Ulcerative (chronic) pancolitis with intestinal obstruction
    BillableCC78 81
  6. K51.013
    Ulcerative (chronic) pancolitis with fistula
    BillableCC81
  7. K51.014
    Ulcerative (chronic) pancolitis with abscess
    BillableCC81
  8. K51.018
    Ulcerative (chronic) pancolitis with other complication
    BillableCC81
  9. K51.019
    Ulcerative (chronic) pancolitis with unspecified complications
    BillableCC81
  10. K51.2
    Ulcerative (chronic) proctitis
    Header
  11. K51.20
    Ulcerative (chronic) proctitis without complications
    BillableCC81
    Inclusion terms 1

    Inclusion terms

    • Ulcerative (chronic) proctitis NOS
  12. K51.21
    Ulcerative (chronic) proctitis with complications
    Header
  13. K51.211
    Ulcerative (chronic) proctitis with rectal bleeding
    BillableCC81
  14. K51.212
    Ulcerative (chronic) proctitis with intestinal obstruction
    BillableCC78 81
  15. K51.213
    Ulcerative (chronic) proctitis with fistula
    BillableCC81
  16. K51.214
    Ulcerative (chronic) proctitis with abscess
    BillableCC81
  17. K51.218
    Ulcerative (chronic) proctitis with other complication
    BillableCC81
  18. K51.219
    Ulcerative (chronic) proctitis with unspecified complications
    BillableCC81
  19. K51.3
    Ulcerative (chronic) rectosigmoiditis
    Header
  20. K51.30
    Ulcerative (chronic) rectosigmoiditis without complications
    BillableCC81
    Inclusion terms 1

    Inclusion terms

    • Ulcerative (chronic) rectosigmoiditis NOS
  21. K51.31
    Ulcerative (chronic) rectosigmoiditis with complications
    Header
  22. K51.311
    Ulcerative (chronic) rectosigmoiditis with rectal bleeding
    BillableCC81
  23. K51.312
    Ulcerative (chronic) rectosigmoiditis with intestinal obstruction
    BillableCC78 81
  24. K51.313
    Ulcerative (chronic) rectosigmoiditis with fistula
    BillableCC81
  25. K51.314
    Ulcerative (chronic) rectosigmoiditis with abscess
    BillableCC81
  26. K51.318
    Ulcerative (chronic) rectosigmoiditis with other complication
    BillableCC81
  27. K51.319
    Ulcerative (chronic) rectosigmoiditis with unspecified complications
    BillableCC81
  28. K51.4
    Inflammatory polyps of colon
    Header
    Excludes2 3

    Excludes2

    • adenomatous polyp of colon (D12.6) D12.6
    • polyposis of colon (D12.6) D12.6
    • polyps of colon NOS (K63.5) K63.5
  29. K51.40
    Inflammatory polyps of colon without complications
    BillableCC81
    Inclusion terms 1

    Inclusion terms

    • Inflammatory polyps of colon NOS
  30. K51.41
    Inflammatory polyps of colon with complications
    Header
  31. K51.411
    Inflammatory polyps of colon with rectal bleeding
    BillableCC81
  32. K51.412
    Inflammatory polyps of colon with intestinal obstruction
    BillableCC78 81
  33. K51.413
    Inflammatory polyps of colon with fistula
    BillableCC81
  34. K51.414
    Inflammatory polyps of colon with abscess
    BillableCC81
  35. K51.418
    Inflammatory polyps of colon with other complication
    BillableCC81
  36. K51.419
    Inflammatory polyps of colon with unspecified complications
    BillableCC81
  37. K51.5
    Left sided colitis
    Header
    Inclusion terms 1

    Inclusion terms

    • Left hemicolitis
  38. K51.50
    Left sided colitis without complications
    BillableCC81
    Inclusion terms 1

    Inclusion terms

    • Left sided colitis NOS
  39. K51.51
    Left sided colitis with complications
    Header
  40. K51.511
    Left sided colitis with rectal bleeding
    BillableCC81
  41. K51.512
    Left sided colitis with intestinal obstruction
    BillableCC78 81
  42. K51.513
    Left sided colitis with fistula
    BillableCC81
  43. K51.514
    Left sided colitis with abscess
    BillableCC81
  44. K51.518
    Left sided colitis with other complication
    BillableCC81
  45. K51.519
    Left sided colitis with unspecified complications
    BillableCC81
  46. K51.8
    Other ulcerative colitis
    Header
  47. K51.80
    Other ulcerative colitis without complications
    BillableCC81
  48. K51.81
    Other ulcerative colitis with complications
    Header
  49. K51.811
    Other ulcerative colitis with rectal bleeding
    BillableCC81
  50. K51.812
    Other ulcerative colitis with intestinal obstruction
    BillableCC78 81
  51. K51.813
    Other ulcerative colitis with fistula
    BillableCC81
  52. K51.814
    Other ulcerative colitis with abscess
    BillableCC81
  53. K51.818
    Other ulcerative colitis with other complication
    BillableCC81
  54. K51.819
    Other ulcerative colitis with unspecified complications
    BillableCC81
  55. K51.9
    Ulcerative colitis, unspecified
    Header
  56. K51.90
    Ulcerative colitis, unspecified, without complications
    BillableCC81
  57. K51.91
    Ulcerative colitis, unspecified, with complications
    Header
  58. K51.911
    Ulcerative colitis, unspecified with rectal bleeding
    BillableCC81
  59. K51.912
    Ulcerative colitis, unspecified with intestinal obstruction
    BillableCC78 81
  60. K51.913
    Ulcerative colitis, unspecified with fistula
    BillableCC81
  61. K51.914
    Ulcerative colitis, unspecified with abscess
    BillableCC81
  62. K51.918
    Ulcerative colitis, unspecified with other complication
    BillableCC81
  63. K51.919
    Ulcerative colitis, unspecified with unspecified complications
    BillableCC81

CC/MCC: as a secondary diagnosis, unless the principal diagnosis is on the code’s PDX exclusion list (MS-DRG v44 Appendix C; list on the code card).

Sources of each column.

Instructions

At K51

Excludes1

  • Crohn's disease [regional enteritis] (K50.-) K50

Use additional code

  • code to identify any associated fistulas, if applicable:
  • anal fistula (K60.3-) K60.3
  • anorectal fistula (K60.5-) K60.5
  • rectal fistula (K60.4-) K60.4
  • code to identify manifestations, such as:
  • pyoderma gangrenosum (L88) L88

Notes that also apply

Block K50-K52 instructions (Includes 1, Excludes1 2): printed on the block page.

Chapter 11 instructions (Excludes2 8): printed on the chapter 11 page.

Index entries

  • Ileocolitisulcerative → K51.0-
  • Pancolitisulcerative (chronic) → K51.00
  • Proctitisulcerative (chronic) → K51.20
  • Rectosigmoiditisulcerative (chronic) → K51.30
  • Inflammation, inflamed, inflammatory (with exudation)polyp, colon → K51.40
  • Colitis (acute) (catarrhal) (chronic) (noninfective) (hemorrhagic)left sided → K51.50
  • Colitis (acute) (catarrhal) (chronic) (noninfective) (hemorrhagic)ulcerative (chronic) → K51.90
  • Polyp, polypuscoloninflammatory → K51.40
  • Colitis (acute) (catarrhal) (chronic) (noninfective) (hemorrhagic)ulcerative (chronic)specified type NEC → K51.80
  • Arthropathyin (due to)ulcerative colitis NEC → K51.90 [M07.6-]
  • Pancolitisulcerative (chronic)withrectal bleeding → K51.011
  • Pancolitisulcerative (chronic)withobstruction → K51.012
  • Pancolitisulcerative (chronic)withfistula → K51.013
  • Pancolitisulcerative (chronic)withabscess → K51.014
  • Pancolitisulcerative (chronic)withspecified complication NEC → K51.018
  • Pancolitisulcerative (chronic)withcomplication → K51.019
  • Proctitisulcerative (chronic)withcomplication → K51.219
  • Rectosigmoiditisulcerative (chronic)withcomplication → K51.319
  • Colitis (acute) (catarrhal) (chronic) (noninfective) (hemorrhagic)left sidedwithrectal bleeding → K51.511
  • Colitis (acute) (catarrhal) (chronic) (noninfective) (hemorrhagic)left sidedwithobstruction → K51.512
  • Colitis (acute) (catarrhal) (chronic) (noninfective) (hemorrhagic)left sidedwithfistula → K51.513
  • Colitis (acute) (catarrhal) (chronic) (noninfective) (hemorrhagic)left sidedwithabscess → K51.514
  • Colitis (acute) (catarrhal) (chronic) (noninfective) (hemorrhagic)left sidedwithcomplication → K51.519
  • Colitis (acute) (catarrhal) (chronic) (noninfective) (hemorrhagic)ulcerative (chronic)withcomplication → K51.919
  • Proctitisulcerative (chronic)withcomplicationrectal bleeding → K51.211
  • Proctitisulcerative (chronic)withcomplicationobstruction → K51.212
  • Proctitisulcerative (chronic)withcomplicationfistula → K51.213
  • Proctitisulcerative (chronic)withcomplicationabscess → K51.214
  • Proctitisulcerative (chronic)withcomplicationspecified NEC → K51.218
  • Rectosigmoiditisulcerative (chronic)withcomplicationrectal bleeding → K51.311
  • Rectosigmoiditisulcerative (chronic)withcomplicationobstruction → K51.312
  • Rectosigmoiditisulcerative (chronic)withcomplicationfistula → K51.313
  • Rectosigmoiditisulcerative (chronic)withcomplicationabscess → K51.314
  • Rectosigmoiditisulcerative (chronic)withcomplicationspecified NEC → K51.318
  • Polyp, polypuscoloninflammatorywithrectal bleeding → K51.411
  • Polyp, polypuscoloninflammatorywithintestinal obstruction → K51.412
  • Polyp, polypuscoloninflammatorywithfistula → K51.413
  • Polyp, polypuscoloninflammatorywithabscess → K51.414
  • Polyp, polypuscoloninflammatorywithcomplication → K51.419
  • Colitis (acute) (catarrhal) (chronic) (noninfective) (hemorrhagic)left sidedwithcomplicationspecified NEC → K51.518

12 more, longer entries are not listed; the search box finds them by word.

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Hierarchy