2027 ICD-10-CM Diagnosis Code B99.9Unspecified infectious disease
ICD-10-CM Codes›A00–B99›B99›B99
- Billable — Valid for Submission
- Not Chronic
ICD-10-CM B99.9
B99.9 is a billable ICD-10-CM diagnosis code for unspecified infectious disease. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 867 through 869. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Parasitic, other specified and unspecified infections.
Code Identity
ICD-10-CM Code
B99.9
Billable Status
Yes — Valid for Submission
Code Describes
Unspecified infectious disease
Short Description
Unspecified infectious disease
Same as the full description in the CMS dataset.
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Abrasion and/or friction burn of anus with infection
- Abrasion and/or friction burn of multiple sites
- Abrasion and/or friction burn of multiple sites, infected
- Abrasion and/or friction burn of vagina with infection
- Abrasion and/or friction burn of vulva with infection
- Abscess of abdominal wall
- Abscess of ankle
- Abscess of aorta
- Abscess of breast, associated with childbirth
- Abscess of bursa of knee
- Abscess of bursa of right knee
- Abscess of bursa of right shoulder
- Abscess of bursa of shoulder
- Abscess of calf
- Abscess of chest wall
- Abscess of knee
- Abscess of lower leg
- Abscess of right foot
- Abscess of skin of abdomen
- Abscess of skin of breast
- Abscess of tendon sheath of hand
- Abscess of tendon sheath of left hand
- Abscess of tendon sheath of right ankle
- Abscess of tendon sheath of right ankle and/or foot
- Abscess of tendon sheath of right foot
- Abscess of thumb
- Abscess of vascular cardiac conduit
- Acoustic neuritis
- Acoustic neuritis due to infectious disease
- Acute confusional state, of infective origin
- Acute endocarditis
- Acute endocarditis of right side of heart due to infection
- Acute infectious conjunctivitis
- Acute infectious disease
- Acute infectious disease of central nervous system
- Acute infectious peritonitis
- Acute infectious tubulointerstitial nephritis
- Acute infective balanitis
- Acute infective endocarditis
- Acute localized peritonitis caused by infection
- Acute nephritis due to another disorder
- Acute pyelonephritis
- Acute symptomatic epileptic seizure due to acute infection of central nervous system
- Acute symptomatic epileptic seizure due to acute infectious disease
- Acute tubulointerstitial nephritis
- Acute tubulointerstitial nephritis associated with systemic infection
- Acute tubulo-interstitial nephritis due to immunological disorder
- Acute urticaria
- Acute urticaria due to infectious disease
- Anemia due to chronic infectious disease
- Anemia due to infection
- Arteriovenous shunt infection
- Arthropathy associated with infection
- Arthropathy associated with nonspecific urethritis
- Autoimmune leukopenia
- Azoospermia due to infectious disease
- Bacterial infection of eye
- Bacterial infectious disease of brain
- Bacterial ulcer of esophagus
- Bacterial vaginosis
- Bacterial vaginosis in pregnancy
- Bilateral acoustic neuritis due to infectious disease
- Bilateral infectious conjunctivitis
- Blistering distal dactylitis
- Brain ventricular shunt infection
- Catheter related bloodstream infection
- Catheter-associated urinary tract infection
- Cauda equina syndrome due to infection
- Cellulitis of elbow
- Cellulitis of finger of left hand
- Cellulitis of left elbow
- Cellulitis of left foot
- Cellulitis of left hand
- Cellulitis of right elbow
- Cellulitis of right foot
- Cellulitis of right hand
- Cerebellar infectious cyst
- Cerebral arteritis
- Cerebral arteritis due to infectious disease
- Chondrolysis of articular cartilage
- Chronic eosinophilic pneumonia due to infection
- Chronic headache due to disorder
- Chronic headache due to infectious disease
- Chronic infection as complication of amputation
- Chronic infectious disease
- Chronic infectious disease of central nervous system
- Chronic infectious pancreatitis
- Chronic infective balanitis
- Chronic orofacial pain
- Chronic orofacial pain due to disorder
- Chronic orofacial pain due to infectious disease
- Chronic osteomyelitis of ankle and/or foot with draining sinus
- Chronic osteomyelitis of ankle with draining sinus
- Chronic osteomyelitis of femur with draining sinus
- Chronic osteomyelitis of foot with draining sinus
- Chronic osteomyelitis of forearm with draining sinus
- Chronic osteomyelitis of hand with draining sinus
- Chronic osteomyelitis of humerus with draining sinus
- Chronic osteomyelitis of lower leg with draining sinus
- Chronic osteomyelitis of right forearm with draining sinus
- Chronic osteomyelitis of shoulder with draining sinus
- Chronic pain in face
- Chronic urticaria
- Chronic urticaria due to infectious disease
- Clinical infection
- Colostomy infection
- Complication associated with cardiac pacemaker lead
- Complication following bariatric surgery
- Complication of totally implantable venous access device
- Complication of transplanted liver
- Congenital hypoplasia of adrenal gland
- Congenital infectious disease
- Congenital nephrotic syndrome due to congenital infection
- Congenital non-bacterial non-viral infection
- Contact lens related corneal infiltrate
- Corneal graft infection
- Cross infection
- Cyst of cerebellar structure
- Defect of articular cartilage
- Dementia due to infectious disease
- Dental prosthesis infection
- Descending necrotizing mediastinitis
- Descending necrotizing mediastinitis due to infection of neck
- Difficulty latching on to breast for feeding
- Dilated cardiomyopathy due to infectious disease
- Disease of presumed infectious origin
- Disorder associated with intra-aortic balloon catheter
- Disorder associated with retained intrauterine contraceptive device
- Disorder associated with surgical mesh
- Disorder due to and following transplant of cornea of left eye
- Disorder due to and following transplant of cornea of right eye
- Disorder of arteriovenous shunt
- Disorder of autonomic nervous system due to infectious disease
- Disorder of bilateral acoustic nerves
- Disorder of brain ventricular shunt
- Disorder of implanted defibrillator generator
- Disorder of implanted penile prosthesis
- Disorder of left patella
- Disorder of right patella
- Disorder of urinary sphincter implant
- Draining sinus co-occurrent and due to chronic osteomyelitis of left hand
- Draining sinus co-occurrent and due to chronic osteomyelitis of left humerus
- Draining sinus co-occurrent and due to chronic osteomyelitis of left lower leg
- Draining sinus co-occurrent and due to chronic osteomyelitis of left shoulder
- Draining sinus co-occurrent and due to chronic osteomyelitis of right hand
- Draining sinus co-occurrent and due to chronic osteomyelitis of right humerus
- Draining sinus co-occurrent and due to chronic osteomyelitis of right lower leg
- Draining sinus co-occurrent and due to chronic osteomyelitis of right shoulder
- Enanthematous infectious disease
- Endocarditis associated with another disorder
- Endocrine infection
- Endogenous lipoid pneumonia due to infectious disease
- Endogenous lipoid pneumonitis
- Endophthalmitis of left eye
- Enterostomy infection
- Eosinophilia due to infectious disease
- Epilepsy due to infectious disease of central nervous system
- Epilepsy due to infectious encephalitis
- Esophagostomy infection
- Exacerbation of allergic asthma due to infection
- Exacerbation of bronchiectasis caused by infection
- Ex-vacuo hydrocephalus due to infection
- Fallopian tube infection
- Febrile urinary tract infection
- Fever due to infection
- Finding of contents of cervix
- Finding related to ability to latch on to breast for feeding
- Focal segmental glomerulosclerosis
- Focal segmental glomerulosclerosis with infectious disease
- Functional intestinal obstruction due to decreased peristalsis
- Functional obstruction of intestine
- Gastric band procedure complication
- Genital infection
- Genitourinary tract infection in pregnancy
- Geotrichum capitatum or Prototheca zopfii
- Glomerular disease due to infectious disease
- Granuloma of spinal cord caused by bacterium
- Healthcare associated infectious disease
- Human immunodeficiency virus infection with secondary clinical infectious disease
- Hydrocephalus ex vacuo
- Immune complex small vessel vasculitis due to infectious disease
- Immune dysregulation, inflammatory bowel disease, arthritis, recurrent infection syndrome
- Immune dysregulation, inflammatory bowel disease, arthritis, recurrent infection, lymphopenia syndrome
- Immunosuppression-related infectious disease
- Implanted defibrillator electrode infection
- Implanted defibrillator generator infection
- Infected aortic graft
- Infected aortofemoral graft
- Infected aortoiliac graft
- Infected hematoma
- Infected hernioplasty mesh
- Infected renal cyst
- Infected seroma due to and following procedure
- Infected umbilical granuloma
- Infection - perineal wound
- Infection after injection
- Infection and inflammation associated with indwelling urinary catheter
- Infection and inflammation associated with retained intrauterine contraceptive device
- Infection and inflammatory reaction due to internal orthopedic fixation device
- Infection AND/OR inflammatory reaction due to internal prosthetic device, implant AND/OR graft
- Infection associated with artificial urinary sphincter
- Infection associated with cardiac implant
- Infection associated with cardiac pacemaker
- Infection associated with cardiac pacemaker electrode
- Infection associated with cardiac pacemaker lead
- Infection associated with cardiac resynchronization therapy implantable defibrillator
- Infection associated with genitourinary device
- Infection associated with implant
- Infection associated with implantable electrode of neurological device
- Infection associated with implanted central nervous system device
- Infection associated with indwelling urinary catheter
- Infection associated with internal fixation device
- Infection associated with intra-aortic balloon catheter
- Infection associated with intrauterine contraceptive device
- Infection associated with musculoskeletal implant
- Infection associated with neurological device
- Infection associated with neurostimulator of spinal cord
- Infection associated with orthopedic device
- Infection associated with peritoneal dialysis catheter
- Infection associated with prosthesis of hip joint
- Infection associated with prosthesis of right hip joint
- Infection associated with prosthetic intervertebral disc
- Infection associated with prosthetic joint of toe of left foot
- Infection associated with prosthetic joint of toe of right foot
- Infection associated with retained intrauterine contraceptive device
- Infection associated with stent of urinary tract
- Infection associated with Tenckhoff catheter
- Infection associated with totally implantable venous access device
- Infection associated with urinary neurostimulator
- Infection associated with vascular device
- Infection associated with vascular implant
- Infection causing abscess of central nervous system
- Infection causing abscess of colon
- Infection causing chondrolysis of articular cartilage
- Infection causing chorea
- Infection causing cyst of central nervous system
- Infection causing granuloma of central nervous system
- Infection causing granuloma of extradural space of spinal cord
- Infection causing granuloma of spinal cord
- Infection causing inflammation of optic nerve
- Infection causing multiple abscesses of brain
- Infection causing myelitis
- Infection causing myoendocarditis
- Infection causing parkinsonism
- Infection causing spinal epidural cyst
- Infection causing spinal subdural cyst
- Infection causing spondyloarthritis
- Infection causing subacute endocarditis
- Infection causing tic
- Infection causing ulcer of stomach
- Infection due to and following peritoneal dialysis
- Infection due to bariatric procedure
- Infection due to gastric band procedure
- Infection involving inner ear
- Infection of arterial graft
- Infection of artery
- Infection of axilla
- Infection of Bartholin gland
- Infection of big toe
- Infection of bilateral eyes
- Infection of biliary tract
- Infection of bite wound
- Infection of bone associated with bone fixation device
- Infection of bone associated with bone wire
- Infection of bone associated with external fixator pin
- Infection of bone associated with internal Kirschner wire fixator
- Infection of bone associated with intramedullary rod
- Infection of bone associated with spinal fixation device
- Infection of bone of foot associated with internal fixation device
- Infection of bone of hand associated with internal fixation device
- Infection of bone of left foot associated with internal fixation device
- Infection of bone of left hand associated with internal fixation device
- Infection of bone of left scapula associated with internal fixation device
- Infection of bone of left thumb associated with internal fixation device
- Infection of bone of left ulna associated with internal fixation device
- Infection of bone of radius and/or ulna
- Infection of bone of right foot associated with internal fixation device
- Infection of bone of right hand associated with internal fixation device
- Infection of bone of right scapula associated with internal fixation device
- Infection of bone of right thumb associated with internal fixation device
- Infection of bone of right ulna associated with internal fixation device
- Infection of bone of scapula associated with internal fixation device
- Infection of bone of thumb associated with internal fixation device
- Infection of bone of ulna associated with internal fixation device
- Infection of brain neurostimulator
- Infection of breast implant
- Infection of calcaneum
- Infection of cardiac resynchronization therapy implantable pacemaker
- Infection of carpal bone
- Infection of catheter exit site
- Infection of central venous catheter exit site
- Infection of conjunctiva of left eye
- Infection of conjunctiva of right eye
- Infection of coronary artery bypass graft
- Infection of cranial bone flap
- Infection of deep tissue at puncture site due to and following peripheral nerve block
- Infection of diaper area
- Infection of female genital system following medically assisted reproduction
- Infection of fibula
- Infection of heart transplant
- Infection of hemodialysis catheter exit site
- Infection of humerus
- Infection of intravenous catheter
- Infection of joint of toe associated with prosthetic joint
- Infection of lacrimal drainage system
- Infection of left breast implant
- Infection of left eye
- Infection of lip
- Infection of liver transplant
- Infection of metatarsal
- Infection of neck
- Infection of nephrostomy catheter
- Infection of nipple associated with childbirth with attachment difficulty
- Infection of nipple associated with lactation
- Infection of nipple, associated with childbirth
- Infection of orbit
- Infection of ovary
- Infection of pacemaker pulse generator site
- Infection of palmar space
- Infection of patella
- Infection of patella associated with internal fixation device
- Infection of peripheral nerve
- Infection of phalanx of finger or thumb
- Infection of phalanx of toe
- Infection of puncture wound
- Infection of radius
- Infection of right breast implant
- Infection of right eye
- Infection of scapula
- Infection of scrotum
- Infection of soft tissue of lumbar spine
- Infection of soft tissue of thoracic spine
- Infection of spermatic cord
- Infection of spleen
- Infection of talus
- Infection of testis and epididymis
- Infection of the breast AND/OR nipple associated with childbirth
- Infection of thoracic spine
- Infection of toenail
- Infection of transplanted cornea of left eye
- Infection of transplanted cornea of right eye
- Infection of transplanted kidney
- Infection of tunnel site of tunneled central venous catheter
- Infection of uncertain etiology
- Infection of urachal remnant
- Infection of urachal sinus
- Infection of ureteral stent
- Infection of urinary bladder catheter
- Infection of vascular catheter
- Infection of ventriculoperitoneal shunt
- Infection of vertebral internal fixation device
- Infection of wound hematoma
- Infection-associated membranous nephropathy
- Infection-induced ileus
- Infection-related hemolytic uremic syndrome
- Infections of the genital tract in pregnancy
- Infectious cirrhosis
- Infectious corneal infiltrates caused by contact lens
- Infectious cyst of cerebral lobe
- Infectious disease
- Infectious disease caused by plant
- Infectious disease in mother complicating childbirth
- Infectious disease of abdomen
- Infectious disease of cardiovascular system
- Infectious disease of central nervous system
- Infectious disease of genitourinary system
- Infectious disease of mother complicating pregnancy
- Infectious disease of mucous membrane
- Infectious disease of nervous system
- Infectious disease of oral mucosa
- Infectious disease with acquired immune deficiency syndrome
- Infectious disorder of cartilage
- Infectious disorder of immune system
- Infectious disorder of the peripheral nervous system
- Infectious edema
- Infectious epithelial keratitis
- Infectious granuloma
- Infectious intermediate uveitis
- Infectious mediastinitis
- Infectious neuroretinitis
- Infectious pancreatitis
- Infectious panuveitis
- Infectious secondary iritis
- Infective cervicitis
- Infective dermatosis of female genitalia
- Infective dermatosis of lip
- Infective disorder of head
- Infective duodenitis
- Infective endocarditis
- Infective epididymitis
- Infective epididymo-orchitis
- Infective occlusion of cerebral artery
- Infective orchitis
- Infective panniculitis
- Infective pleurisy
- Infective stricture of esophagus
- Infective ulcer of esophagus
- Infertility due to infection
- Inflammation associated with cardiac implant
- Inflammation associated with genitourinary device
- Inflammation associated with indwelling urinary catheter
- Inflammation associated with internal fixation device
- Inflammation associated with musculoskeletal implant
- Inflammation associated with retained intrauterine contraceptive device
- Injection site infection
- Instability of spine due to infectious disorder
- Intermediate uveitis
- Intracranial infectious cyst
- Invasive infectious disease
- Isolated cervical dystonia
- Keratitis caused by infection
- Left acoustic neuritis due to infectious disease
- Left patella infection associated with internal fixation device
- Left sided infective endocarditis
- Line sepsis associated with dialysis catheter
- Liver disorder due to infection
- Local infection of wound
- Localized enamel hypoplasia
- Localized enamel hypoplasia associated with local infection
- Localized infection
- Localized infection associated with central venous catheter
- Lyell syndrome
- Lymphedema due to infection
- Lymphedema due to recurrent infection
- Lymphocyte count below reference range
- Lymphocytopenia
- Lymphopenia due to infection
- Magnusiomyces capitatus or Prototheca zopfii or Pichia kudriavzevii
- Malabsorption caused by infective agent
- Male accessory gland infection
- Male genital infection
- Malformation of urachus
- Masked infection
- Micrognathia, recurrent infections, behavioral abnormalities, mild intellectual disability syndrome
- Minimal change disease
- Minimal change disease due to infectious disease
- MIRAGE syndrome
- Mixed infectious disease
- Multiple abscesses
- Multiple infected superficial wounds
- Myocarditis due to infectious agent
- Named sign of foot
- Necrotizing soft tissue infection
- Neonatal acute symptomatic epileptic seizure due to acute infectious disease
- Neonatal dacryocystitis
- Neuropathy due to infection
- Neuropathy of upper limb due to infection
- Neuroretinitis
- Neutropenia associated with infectious disease
- Nipple infection
- Nodule of umbilical structure
- Nonpurulent mastitis associated with childbirth
- Nonpurulent mastitis associated with childbirth with attachment difficulty
- Nonunion of ankle joint with infection
- Nonunion of joint of foot with infection
- Nonvenomous insect bite of left hand with infection
- Nonvenomous insect bite of right hand with infection
- Obstetric abscess of breast
- Obstetric infection of breast
- Obstetric nipple infection
- Obstetric non-purulent mastitis
- Oligozoospermia
- Oligozoospermia due to infection
- Omphalitis
- Onychia
- Opportunistic infectious disease
- Oral mucosal bacterial disease
- Organ surgical site infection
- Osler's node of foot
- Osler's node of hand
- Osteomyelitis of left hand
- Osteomyelitis of left humerus
- Osteomyelitis of left shoulder
- Osteomyelitis of right hand
- Osteomyelitis of right humerus
- Osteomyelitis of right shoulder
- Osteomyelitis of upper arm
- Overwhelming infection in asplenic patient
- Palmar space infection, hypothenar
- Palmar space infection, mid-palm
- Palmar space infection, thenar
- Paraspinal abscess
- Parkinsonism co-occurrent and due to acute infection
- Paronychia of left thumb
- Paronychia of thumb
- Pathogen-negative nonspecific genital infection
- Penile prosthesis infection
- Perianal infection
- Periendocarditis due to infection
- Peritoneal dialysis catheter exit site infection
- Peritoneal dialysis catheter tunnel infection
- Persistent infection
- Post procedure puncture site infection
- Posterior uveitis due to infectious disease
- Postoperative infection of bloodstream associated with vascular catheter
- Postoperative urinary tract infection
- Postoperative wound infection
- Postoperative wound infection-deep
- Postpartum abscess of breast
- Postprocedural septic shock
- Poststernotomy mediastinitis
- Post-traumatic wound infection
- Prosthetic valve endocarditis
- Pulp abscess of thumb
- Pulp space infection of finger/thumb
- Pulp space infection of toe
- Purulent endocarditis
- Pus at uterine os cervix
- Pyelonephritis associated with another disorder
- Pyogenic hydrocephalus
- Pyogenic pericarditis
- Reactive infectious mucocutaneous eruption
- Recurrent infection due to immunoglobulin isotype deficiency
- Recurrent infection due to specific granule deficiency
- Recurrent infection in childhood
- Recurrent infectious disease
- Recurrent opportunistic infection
- Right acoustic neuritis due to infectious disease
- Right patella infection associated with internal fixation device
- Right sided infective endocarditis
- Scalp infection
- Scarring alopecia due to infectious disease
- Secondary chronic eosinophilic pneumonia
- Secondary eosinophilia
- Secondary infection
- Secondary tic disorder
- Sepsis due to ectopic pregnancy
- Sepsis in asplenic subject
- Seroma
- Seroma following procedure
- Short stature co-occurrent and due to endocrine disorder
- Small vessel vasculitis caused by immune complex
- Spasmodic torticollis
- Spasmodic torticollis due to infection
- Stevens-Johnson syndrome, toxic epidermal necrolysis spectrum
- Stricture of esophagus
- Subacute endocarditis
- Subacute endocarditis of right side of heart due to infection
- Subacute infectious disease
- Subclinical disease AND/OR syndrome
- Subclinical infection
- Subcutaneous abscess of knee
- Superficial injuries involving multiple body regions
- Superficial injury of anus with infection
- Superficial injury of back with infection
- Superficial injury of upper arm with infection
- Superficial injury of vagina with infection
- Superficial injury of vulva with infection
- Superficial puncture wound
- Superficial soft tissue infection at site of neuraxial block
- Superficial soft tissue infection at site of peripheral nerve block
- Superimposed infection
- Suprapubic abscess
- Testicular prosthesis infection
- Therapy failure due to antibiotic resistance
- Thumb onychia
- Toxic epidermal necrolysis due to infection
- Transfusion-transmitted infectious disease
- Ulcer of duodenum due to infection
- Umbilical granuloma
- Urachal abscess
- Urachal sinus
- Urinary tract infection following delivery
- Urticaria secondary to infection
- Vaginitis in pregnancy
- Vomiting co-occurrent and due to infectious disease
- Water-borne infectious disease
- White matter disorder caused by infection
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to B99.9: its own notes plus those printed at Chapter 1. A note printed at a category, block or chapter applies to every code under it.
Includes
Further defines, or gives examples of, the content of the category.
- diseases generally recognized as communicable or transmissible
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
- carrier or suspected carrier of infectious disease (Z22.-)
- certain localized infections - see body system-related chapters
- infectious and parasitic diseases complicating pregnancy, childbirth and the puerperium (O98.-)
- infectious and parasitic diseases specific to the perinatal period (P35-P39)
- influenza and other acute respiratory infections (J00-J22)
Use Additional Code
Add a second code, after this one, to fully describe the condition.
- code to identify resistance to antimicrobial drugs (Z16.-)
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name B99.9, its category, or a range that includes it.
Applicable To 2
These notes mention B99.9.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Disease, diseased See Also: Syndrome;
epidemic B99.9
infectious, infective B99.9
infectious B99.9
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
CCSR INF009
Parasitic, other specified and unspecified infections
Default principal diagnosis: inpatient Yes · outpatient Yes
Clinical InformationClinical
Infections
invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases.
Patient EducationClinical
Infectious Diseases
Germs, or microbes, are found everywhere - in the air, soil, and water. There are also germs on your skin and in your body. Many of them are harmless, and some can even be helpful. But some of them can make you sick. Infectious diseases are diseases that are caused by germs.
The full article covers:
- What are infectious diseases?
- What are the different types of germs that cause infectious diseases?
- How can you get infectious diseases?
- What are the symptoms of infectious diseases?
- What are the treatments for infectious diseases?
- Can infectious diseases be prevented?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert B99.9 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.
Questions About B99.9Overview
What is the ICD-10 code for unspecified infectious disease?
The ICD-10-CM code for unspecified infectious disease is B99.9 (sometimes written as B999). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is B99.9 (Other and unspecified infectious diseases) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report unspecified infectious disease on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does B99.9 group to?
When unspecified infectious disease is the principal diagnosis on an inpatient stay, it groups to MS-DRG 867, 869, 868, with relative weights from 0.6784 to 2.1855 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of B99.9?
Under the General Equivalence Mappings, unspecified infectious disease converts to ICD-9-CM 136.9 (infect/parasite dis NOS). The mapping is approximate, so confirm the match fits the documentation.
