K12.3
Non-Billable

Oral mucositis (ulcerative)

Non-Billable / Non-Specific Code

What is Oral mucositis (ulcerative)?

ICD-10-CM K12.3 is the diagnosis code for Oral mucositis (ulcerative). This code falls under the section "Diseases of oral cavity and salivary glands" within Chapter 11 — Diseases of the digestive system (K00-K95). It is a non-billable/non-specific ICD-10-CM code that should not be used for reimbursement. A more specific sub-code is required for billing. Medical coders and healthcare providers use this code to document and classify diagnoses in electronic health records, insurance claims, and clinical databases.

💡 Inclusions
â„šī¸ Excludes2

Coding Guidelines for K12.3

✅ This Code Includes

  • Mucositis (oral) (oropharyneal)

â„šī¸ Type 2 Excludes (Code separately if applicable)

The following conditions are not included in K12.3. If the patient has both, code each condition separately:

  • gastrointestinal mucositis (ulcerative) (K92.81)
  • mucositis (ulcerative) of vagina and vulva (N76.81)
  • nasal mucositis (ulcerative) (J34.81)

ICD-10-CM Code Hierarchy

Understanding where K12.3 sits in the ICD-10-CM classification helps ensure proper coding:

Current CodeK12.3 — Oral mucositis (ulcerative)
Sub-Codes (1918)
A00A01A02A03A04A05A06A07A08A09A15A17A18A19A20A21A22A23A24A25A26A27A28A30A31A32A33A34A35A36A37A38A39A40A41A42A43A44A46A48A49A50A51A52A53A54A55A56A57A58A59A60A63A64A65A66A67A68A69A70A71A74A75A77A78A79A80A81A82A83A84A85A86A87A88A89A90A91A92A93A94A95A96A98A99B00B01B02B03B04B05B06B07B08B09B10B15B16B17B18B19B20B25B26B27B30B33B34B35B36B37B38B39B40B41B42B43B44B45B46B47B48B49B50B51B52B53B54B55B56B57B58B59B60B64B65B66B67B68B69B70B71B72B73B74B75B76B77B78B79B80B81B82B83B85B86B87B88B89B90B91B92B94B95B96B97B99C00C01C02C03C04C05C06C07C08C09C10C11C12C13C14C15C16C17C18C19C20C21C22C23C24C25C26C30C31C32C33C34C37C38C39C40C41C43C44C45C46C47C48C49C4AC50C51C52C53C54C55C56C57C58C60C61C62C63C64C65C66C67C68C69C70C71C72C73C74C75C76C77C78C79C7AC7BC80C81C82C83C84C85C86C88C90C91C92C93C94C95C96D00D01D02D03D04D05D06D07D09D10D11D12D13D14D15D16D17D18D19D20D21D22D23D24D25D26D27D28D29D30D31D32D33D34D35D36D37D38D39D3AD40D41D42D43D44D45D46D47D48D49D50D51D52D53D55D56D57D58D59D60D61D62D63D64D65D66D67D68D69D70D71D72D73D74D75D76D77D78D80D81D82D83D84D86D89E00E01E02E03E04E05E06E07E08E09E10E11E13E15E16E20E21E22E23E24E25E26E27E28E29E30E31E32E34E35E36E40E41E42E43E44E45E46E50E51E52E53E54E55E56E58E59E60E61E63E64E65E66E67E68E70E71E72E73E74E75E76E77E78E79E80E83E84E85E86E87E88E89F01F02F03F04F05F06F07F09F10F11F12F13F14F15F16F17F18F19F20F21F22F23F24F25F28F29F30F31F32F33F34F39F40F41F42F43F44F45F48F50F51F52F53F54F55F59F60F63F64F65F66F68F69F70F71F72F73F78F79F80F81F82F84F88F89F90F91F93F94F95F98F99G00G01G02G03G04G05G06G07G08G09G10G11G12G13G14G20G21G23G24G25G26G30G31G32G35G36G37G40G43G44G45G46G47G50G51G52G53G54G55G56G57G58G59G60G61G62G63G64G65G70G71G72G73G80G81G82G83G89G90G91G92G93G94G95G96G97G98G99H00H01H02H04H05H10H11H15H16H17H18H20H21H22H25H26H27H28H30H31H32H33H34H35H36H40H42H43H44H46H47H49H50H51H52H53H54H55H57H59H60H61H62H65H66H67H68H69H70H71H72H73H74H75H80H81H82H83H90H91H92H93H94H95I00I01I02I05I06I07I08I09I10I11I12I13I15I16I1AI20I21I22I23I24I25I26I27I28I30I31I32I33I34I35I36I37I38I39I40I41I42I43I44I45I46I47I48I49I50I51I52I5AI60I61I62I63I65I66I67I68I69I70I71I72I73I74I75I76I77I78I79I80I81I82I83I85I86I87I88I89I95I96I97I99J00J01J02J03J04J05J06J09J10J11J12J13J14J15J16J17J18J20J21J22J30J31J32J33J34J35J36J37J38J39J40J41J42J43J44J45J47J4AJ60J61J62J63J64J65J66J67J68J69J70J80J81J82J84J85J86J90J91J92J93J94J95J96J98J99K00K01K02K03K04K05K06K08K09K11K12K13K14K20K21K22K23K25K26K27K28K29K30K31K35K36K37K38K40K41K42K43K44K45K46K50K51K52K55K56K57K58K59K60K61K62K63K64K65K66K67K68K70K71K72K73K74K75K76K77K80K81K82K83K85K86K87K90K91K92K94K95L00L01L02L03L04L05L08L10L11L12L13L14L20L21L22L23L24L25L26L27L28L29L30L40L41L42L43L44L45L49L50L51L52L53L54L55L56L57L58L59L60L62L63L64L65L66L67L68L70L71L72L73L74L75L76L80L81L82L83L84L85L86L87L88L89L90L91L92L93L94L95L97L98L99M00M01M02M04M05M06M07M08M10M11M12M13M14M15M16M17M18M19M1AM20M21M22M23M24M25M26M27M30M31M32M33M34M35M36M40M41M42M43M45M46M47M48M49M50M51M53M54M60M61M62M63M65M66M67M70M71M72M75M76M77M79M80M81M83M84M85M86M87M88M89M90M91M92M93M94M95M96M97M99N00N01N02N03N04N05N06N07N08N10N11N12N13N14N15N16N17N18N19N20N21N22N23N25N26N27N28N29N30N31N32N33N34N35N36N37N39N40N41N42N43N44N45N46N47N48N49N50N51N52N53N60N61N62N63N64N65N70N71N72N73N74N75N76N77N80N81N82N83N84N85N86N87N88N89N90N91N92N93N94N95N96N97N98N99O00O01O02O03O04O07O08O09O10O11O12O13O14O15O16O20O21O22O23O24O25O26O28O29O30O31O32O33O34O35O36O40O41O42O43O44O45O46O47O48O60O61O62O63O64O65O66O67O68O69O70O71O72O73O74O75O76O77O80O82O85O86O87O88O89O90O91O92O94O98O99O9AP00P01P02P03P04P05P07P08P09P10P11P12P13P14P15P19P22P23P24P25P26P27P28P29P35P36P37P38P39P50P51P52P53P54P55P56P57P58P59P60P61P70P71P72P74P76P77P78P80P81P83P84P90P91P92P93P94P95P96Q00Q01Q02Q03Q04Q05Q06Q07Q10Q11Q12Q13Q14Q15Q16Q17Q18Q20Q21Q22Q23Q24Q25Q26Q27Q28Q30Q31Q32Q33Q34Q35Q36Q37Q38Q39Q40Q41Q42Q43Q44Q45Q50Q51Q52Q53Q54Q55Q56Q60Q61Q62Q63Q64Q65Q66Q67Q68Q69Q70Q71Q72Q73Q74Q75Q76Q77Q78Q79Q80Q81Q82Q83Q84Q85Q86Q87Q89Q90Q91Q92Q93Q95Q96Q97Q98Q99QA0R00R01R03R04R05R06R07R09R10R11R12R13R14R15R16R17R18R19R20R21R22R23R25R26R27R29R30R31R32R33R34R35R36R37R39R40R41R42R43R44R45R46R47R48R49R50R51R52R53R54R55R56R57R58R59R60R61R62R63R64R65R68R69R70R71R73R74R75R76R77R78R79R80R81R82R83R84R85R86R87R88R89R90R91R92R93R94R97R99S00S01S02S03S04S05S06S07S08S09S10S11S12S13S14S15S16S17S19S20S21S22S23S24S25S26S27S28S29S30S31S32S33S34S35S36S37S38S39S40S41S42S43S44S45S46S47S48S49S50S51S52S53S54S55S56S57S58S59S60S61S62S63S64S65S66S67S68S69S70S71S72S73S74S75S76S77S78S79S80S81S82S83S84S85S86S87S88S89S90S91S92S93S94S95S96S97S98S99T07T14T15T16T17T18T19T20T21T22T23T24T25T26T27T28T30T31T32T33T34T36T37T38T39T40T41T42T43T44T45T46T47T48T49T50T51T52T53T54T55T56T57T58T59T60T61T62T63T64T65T66T67T68T69T70T71T73T74T75T76T78T79T80T81T82T83T84T85T86T87T88U07U09V00V01V02V03V04V05V06V09V10V11V12V13V14V15V16V17V18V19V20V21V22V23V24V25V26V27V28V29V30V31V32V33V34V35V36V37V38V39V40V41V42V43V44V45V46V47V48V49V50V51V52V53V54V55V56V57V58V59V60V61V62V63V64V65V66V67V68V69V70V71V72V73V74V75V76V77V78V79V80V81V82V83V84V85V86V87V88V89V90V91V92V93V94V95V96V97V98V99W00W01W03W04W05W06W07W08W09W10W11W12W13W1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Sub-Codes 5 entries
K12.30Oral mucositis (ulcerative), unspecifiedBillableK12.31Oral mucositis (ulcerative) due to antineoplastic therapyBillableK12.32Oral mucositis (ulcerative) due to other drugsBillableK12.33Oral mucositis (ulcerative) due to radiationBillableK12.39Other oral mucositis (ulcerative)Billable
Related Codes

Frequently Asked Questions

Is K12.3 a billable ICD-10-CM code?

No, K12.3 is a non-billable/non-specific code. You should use a more specific sub-code for billing and reimbursement.

What does K12.3 mean?

K12.3 is the ICD-10-CM diagnosis code for "Oral mucositis (ulcerative)". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.

What is the parent code of K12.3?

The parent code of K12.3 is K12 ("Stomatitis and related lesions"). K12.3 provides a more specific classification within this category.

What section is K12.3 in?

K12.3 is located in Section K00-K14 — "Diseases of oral cavity and salivary glands" within Chapter 11 of the ICD-10-CM Tabular List.

What are the sub-codes of K12.3?

K12.3 has 1918 sub-code(s) that provide more specific detail: A00, A01, A02, A03, A04 and more.

When should I use K12.3?

Use K12.3 when the patients documented diagnosis matches "Oral mucositis (ulcerative)" and the clinical documentation supports this level of specificity. Always verify with the latest ICD-10-CM guidelines and payer requirements.

People Also Ask

What is the ICD-10 code for Oral mucositis (ulcerative)?

The ICD-10-CM code for Oral mucositis (ulcerative) is K12.3.

Can K12.3 be used for primary diagnosis?

No, K12.3 is non-billable. Use a more specific sub-code for primary diagnosis billing.

What chapter is K12.3 in?

K12.3 is in Chapter 11 of the ICD-10-CM Tabular List.

Is K12.3 valid for 2026?

Yes, K12.3 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.

See Also

← PreviousK12.2Cellulitis and abscess of mouthNext →K12.30Oral mucositis (ulcerative), unspecified
Code Details
K12.3
Oral mucositis (ulcerative)
Non-Billable / Non-Specific Code
11 — Diseases of the digestive system (K00-K95)
K00-K14 — Diseases of oral cavity and salivary glands
2026 ICD-10-CM