Convert to ICD-10-CM: 
543.9 converts approximately to:
- 2015/16 ICD-10-CM K38.1 Appendicular concretionsOr: 
- 2015/16 ICD-10-CM K38.2 Diverticulum of appendixOr: 
- 2015/16 ICD-10-CM K38.3 Fistula of appendixOr: 
- 2015/16 ICD-10-CM K38.8 Other specified diseases of appendixOr: 
- 2015/16 ICD-10-CM K38.9 Disease of appendix, unspecified
 ICD-9-CM Volume 2 Index entries containing back-references to 
543.9:
- Adhesion(s), adhesive (postinfectional) (postoperative) appendix 543.9 appendix 543.9
 
- Appendiclausis 543.9
- Appendicolithiasis 543.9
- Atrophy, atrophic appendix 543.9 appendix 543.9
 
- Calculus, calculi, calculous 592.9  appendix 543.9 appendix 543.9
 
- Colic (recurrent) 789.0  appendicular 543.9 appendicular 543.9
  appendix 543.9 appendix 543.9
  vermicular 543.9 vermicular 543.9
 
- Concretion - see also Calculus appendicular 543.9 appendicular 543.9
 
- Cyst (mucus) (retention) (serous) (simple) appendix 543.9 appendix 543.9
 
- Dilatation appendix (cystic) 543.9 appendix (cystic) 543.9
 
- Disease, diseased - see also Syndrome appendix 543.9 appendix 543.9
 
- Diverticula, diverticulosis, diverticulum (acute) (multiple) (perforated) (ruptured) 562.10  appendix (noninflammatory) 543.9 appendix (noninflammatory) 543.9
 
- Fecalith (impaction) 560.39  appendix 543.9 appendix 543.9
 
- Fibrosis, fibrotic appendix, appendiceal, noninflammatory 543.9 appendix, appendiceal, noninflammatory 543.9
  periappendiceal 543.9 periappendiceal 543.9
 
- Fistula (sinus) 686.9  appendix, appendicular 543.9 appendix, appendicular 543.9
 
- Granuloma NEC 686.1  appendix 543.9 appendix 543.9
 
- Intussusception (colon) (enteric) (intestine) (rectum) 560.0  appendix 543.9 appendix 543.9
 
- Kink, kinking appendix 543.9 appendix 543.9
 
- Mucocele appendix 543.9 appendix 543.9
 
- Obliteration appendix (lumen) 543.9 appendix (lumen) 543.9
 
- Sloughing (multiple) (skin) 686.9  appendix 543.9 appendix 543.9
 
- Stercolith (see also Fecalith) 560.39  appendix 543.9 appendix 543.9
 
- Strangulation, strangulated 994.7  appendix 543.9 appendix 543.9