M21.2
Non-Billable

Flexion deformity

Non-Billable / Non-Specific Code

What is Flexion deformity?

ICD-10-CM M21.2 is the diagnosis code for Flexion deformity. This code falls under the section "Other joint disorders" within Chapter 13 — Diseases of the musculoskeletal system and connective tissue (M00-M99). 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.

Coding Guidelines for M21.2

Always refer to the official ICD-10-CM Tabular List for complete coding guidelines. Ensure documentation supports the specificity of the code selected. When in doubt, consult a certified medical coder or the latest CMS guidelines.

ICD-10-CM Code Hierarchy

Understanding where M21.2 sits in the ICD-10-CM classification helps ensure proper coding:

Current CodeM21.2 — Flexion deformity
Sub-Codes (1918)
A00A01A02A03A04A05A06A07A08A09A15A17A18A19A20A21A22A23A24A25A26A27A28A30A31A32A33A34A35A36A37A38A39A40A41A42A43A44A46A48A49A50A51A52A53A54A55A56A57A58A59A60A63A64A65A66A67A68A69A70A71A74A75A77A78A79A80A81A82A83A84A85A86A87A88A89A90A91A92A93A94A95A96A98A99B00B01B02B03B04B05B06B07B08B09B10B15B16B17B18B19B20B25B26B27B30B33B34B35B36B37B38B39B40B41B42B43B44B45B46B47B48B49B50B51B52B53B54B55B56B57B58B59B60B64B65B66B67B68B69B70B71B72B73B74B75B76B77B78B79B80B81B82B83B85B86B87B88B89B90B91B92B94B95B96B97B99C00C01C02C03C04C05C06C07C08C09C10C11C12C13C14C15C16C17C18C19C20C21C22C23C24C25C26C30C31C32C33C34C37C38C39C40C41C43C44C45C46C47C48C49C4AC50C51C52C53C54C55C56C57C58C60C61C62C63C64C65C66C67C68C69C70C71C72C73C74C75C76C77C78C79C7AC7BC80C81C82C83C84C85C86C88C90C91C92C93C94C95C96D00D01D02D03D04D05D06D07D09D10D11D12D13D14D15D16D17D18D19D20D21D22D23D24D25D26D27D28D29D30D31D32D33D34D35D36D37D38D39D3AD40D41D42D43D44D45D46D47D48D49D50D51D52D53D55D56D57D58D59D60D61D62D63D64D65D66D67D68D69D70D71D72D73D74D75D76D77D78D80D81D82D83D84D86D89E00E01E02E03E04E05E06E07E08E09E10E11E13E15E16E20E21E22E23E24E25E26E27E28E29E30E31E32E34E35E36E40E41E42E43E44E45E46E50E51E52E53E54E55E56E58E59E60E61E63E64E65E66E67E68E70E71E72E73E74E75E76E77E78E79E80E83E84E85E86E87E88E89F01F02F03F04F05F06F07F09F10F11F12F13F14F15F16F17F18F19F20F21F22F23F24F25F28F29F30F31F32F33F34F39F40F41F42F43F44F45F48F50F51F52F53F54F55F59F60F63F64F65F66F68F69F70F71F72F73F78F79F80F81F82F84F88F89F90F91F93F94F95F98F99G00G01G02G03G04G05G06G07G08G09G10G11G12G13G14G20G21G23G24G25G26G30G31G32G35G36G37G40G43G44G45G46G47G50G51G52G53G54G55G56G57G58G59G60G61G62G63G64G65G70G71G72G73G80G81G82G83G89G90G91G92G93G94G95G96G97G98G99H00H01H02H04H05H10H11H15H16H17H18H20H21H22H25H26H27H28H30H31H32H33H34H35H36H40H42H43H44H46H47H49H50H51H52H53H54H55H57H59H60H61H62H65H66H67H68H69H70H71H72H73H74H75H80H81H82H83H90H91H92H93H94H95I00I01I02I05I06I07I08I09I10I11I12I13I15I16I1AI20I21I22I23I24I25I26I27I28I30I31I32I33I34I35I36I37I38I39I40I41I42I43I44I45I46I47I48I49I50I51I52I5AI60I61I62I63I65I66I67I68I69I70I71I72I73I74I75I76I77I78I79I80I81I82I83I85I86I87I88I89I95I96I97I99J00J01J02J03J04J05J06J09J10J11J12J13J14J15J16J17J18J20J21J22J30J31J32J33J34J35J36J37J38J39J40J41J42J43J44J45J47J4AJ60J61J62J63J64J65J66J67J68J69J70J80J81J82J84J85J86J90J91J92J93J94J95J96J98J99K00K01K02K03K04K05K06K08K09K11K12K13K14K20K21K22K23K25K26K27K28K29K30K31K35K36K37K38K40K41K42K43K44K45K46K50K51K52K55K56K57K58K59K60K61K62K63K64K65K66K67K68K70K71K72K73K74K75K76K77K80K81K82K83K85K86K87K90K91K92K94K95L00L01L02L03L04L05L08L10L11L12L13L14L20L21L22L23L24L25L26L27L28L29L30L40L41L42L43L44L45L49L50L51L52L53L54L55L56L57L58L59L60L62L63L64L65L66L67L68L70L71L72L73L74L75L76L80L81L82L83L84L85L86L87L88L89L90L91L92L93L94L95L97L98L99M00M01M02M04M05M06M07M08M10M11M12M13M14M15M16M17M18M19M1AM20M21M22M23M24M25M26M27M30M31M32M33M34M35M36M40M41M42M43M45M46M47M48M49M50M51M53M54M60M61M62M63M65M66M67M70M71M72M75M76M77M79M80M81M83M84M85M86M87M88M89M90M91M92M93M94M95M96M97M99N00N01N02N03N04N05N06N07N08N10N11N12N13N14N15N16N17N18N19N20N21N22N23N25N26N27N28N29N30N31N32N33N34N35N36N37N39N40N41N42N43N44N45N46N47N48N49N50N51N52N53N60N61N62N63N64N65N70N71N72N73N74N75N76N77N80N81N82N83N84N85N86N87N88N89N90N91N92N93N94N95N96N97N98N99O00O01O02O03O04O07O08O09O10O11O12O13O14O15O16O20O21O22O23O24O25O26O28O29O30O31O32O33O34O35O36O40O41O42O43O44O45O46O47O48O60O61O62O63O64O65O66O67O68O69O70O71O72O73O74O75O76O77O80O82O85O86O87O88O89O90O91O92O94O98O99O9AP00P01P02P03P04P05P07P08P09P10P11P12P13P14P15P19P22P23P24P25P26P27P28P29P35P36P37P38P39P50P51P52P53P54P55P56P57P58P59P60P61P70P71P72P74P76P77P78P80P81P83P84P90P91P92P93P94P95P96Q00Q01Q02Q03Q04Q05Q06Q07Q10Q11Q12Q13Q14Q15Q16Q17Q18Q20Q21Q22Q23Q24Q25Q26Q27Q28Q30Q31Q32Q33Q34Q35Q36Q37Q38Q39Q40Q41Q42Q43Q44Q45Q50Q51Q52Q53Q54Q55Q56Q60Q61Q62Q63Q64Q65Q66Q67Q68Q69Q70Q71Q72Q73Q74Q75Q76Q77Q78Q79Q80Q81Q82Q83Q84Q85Q86Q87Q89Q90Q91Q92Q93Q95Q96Q97Q98Q99QA0R00R01R03R04R05R06R07R09R10R11R12R13R14R15R16R17R18R19R20R21R22R23R25R26R27R29R30R31R32R33R34R35R36R37R39R40R41R42R43R44R45R46R47R48R49R50R51R52R53R54R55R56R57R58R59R60R61R62R63R64R65R68R69R70R71R73R74R75R76R77R78R79R80R81R82R83R84R85R86R87R88R89R90R91R92R93R94R97R99S00S01S02S03S04S05S06S07S08S09S10S11S12S13S14S15S16S17S19S20S21S22S23S24S25S26S27S28S29S30S31S32S33S34S35S36S37S38S39S40S41S42S43S44S45S46S47S48S49S50S51S52S53S54S55S56S57S58S59S60S61S62S63S64S65S66S67S68S69S70S71S72S73S74S75S76S77S78S79S80S81S82S83S84S85S86S87S88S89S90S91S92S93S94S95S96S97S98S99T07T14T15T16T17T18T19T20T21T22T23T24T25T26T27T28T30T31T32T33T34T36T37T38T39T40T41T42T43T44T45T46T47T48T49T50T51T52T53T54T55T56T57T58T59T60T61T62T63T64T65T66T67T68T69T70T71T73T74T75T76T78T79T80T81T82T83T84T85T86T87T88U07U09V00V01V02V03V04V05V06V09V10V11V12V13V14V15V16V17V18V19V20V21V22V23V24V25V26V27V28V29V30V31V32V33V34V35V36V37V38V39V40V41V42V43V44V45V46V47V48V49V50V51V52V53V54V55V56V57V58V59V60V61V62V63V64V65V66V67V68V69V70V71V72V73V74V75V76V77V78V79V80V81V82V83V84V85V86V87V88V89V90V91V92V93V94V95V96V97V98V99W00W01W03W04W05W06W07W08W09W10W11W12W13W14W15W16W17W18W19W20W21W22W23W24W25W26W27W28W29W30W31W32W33W34W35W36W37W38W39W40W42W44W45W46W49W50W51W52W53W54W55W56W57W58W59W60W61W62W64W65W67W69W73W74W85W86W88W89W90W92W93W94W99X00X01X02X03X04X05X06X08X10X11X12X13X14X15X16X17X18X19X30X31X32X34X35X36X37X38X39X50X52X58X71X72X73X74X75X76X77X78X79X80X81X82X83X92X93X94X95X96X97X98X99Y00Y01Y02Y03Y04Y07Y08Y09Y21Y22Y23Y24Y25Y26Y27Y28Y29Y30Y31Y32Y33Y35Y36Y37Y38Y62Y63Y64Y65Y66Y69Y70Y71Y72Y73Y74Y75Y76Y77Y78Y79Y80Y81Y82Y83Y84Y90Y92Y93Y95Y99Z00Z01Z02Z03Z04Z05Z08Z09Z11Z12Z13Z14Z15Z16Z17Z18Z19Z20Z21Z22Z23Z28Z29Z30Z31Z32Z33Z34Z36Z37Z38Z39Z3AZ40Z41Z42Z43Z44Z45Z46Z47Z48Z49Z51Z52Z53Z55Z56Z57Z58Z59Z60Z62Z63Z64Z65Z66Z67Z68Z69Z70Z71Z72Z73Z74Z75Z76Z77Z78Z79Z80Z81Z82Z83Z84Z85Z86Z87Z88Z89Z90Z91Z92Z93Z94Z95Z96Z97Z98Z99
Sub-Codes 8 entries
M21.20Flexion deformity, unspecified siteBillableM21.21Flexion deformity, shoulderNon-BillableM21.211Flexion deformity, right shoulderBillableM21.212Flexion deformity, left shoulderBillableM21.219Flexion deformity, unspecified shoulderBillableM21.22Flexion deformity, elbowNon-BillableM21.221Flexion deformity, right elbowBillableM21.222Flexion deformity, left elbowBillableM21.229Flexion deformity, unspecified elbowBillableM21.23Flexion deformity, wristNon-BillableM21.231Flexion deformity, right wristBillableM21.232Flexion deformity, left wristBillableM21.239Flexion deformity, unspecified wristBillableM21.24Flexion deformity, finger jointsNon-BillableM21.241Flexion deformity, right finger jointsBillableM21.242Flexion deformity, left finger jointsBillableM21.249Flexion deformity, unspecified finger jointsBillableM21.25Flexion deformity, hipNon-BillableM21.251Flexion deformity, right hipBillableM21.252Flexion deformity, left hipBillableM21.259Flexion deformity, unspecified hipBillableM21.26Flexion deformity, kneeNon-BillableM21.261Flexion deformity, right kneeBillableM21.262Flexion deformity, left kneeBillableM21.269Flexion deformity, unspecified kneeBillableM21.27Flexion deformity, ankle and toesNon-BillableM21.271Flexion deformity, right ankle and toesBillableM21.272Flexion deformity, left ankle and toesBillableM21.279Flexion deformity, unspecified ankle and toesBillable
Related Codes

Frequently Asked Questions

Is M21.2 a billable ICD-10-CM code?

No, M21.2 is a non-billable/non-specific code. You should use a more specific sub-code for billing and reimbursement.

What does M21.2 mean?

M21.2 is the ICD-10-CM diagnosis code for "Flexion deformity". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.

What is the parent code of M21.2?

The parent code of M21.2 is M21 ("Other acquired deformities of limbs"). M21.2 provides a more specific classification within this category.

What section is M21.2 in?

M21.2 is located in Section M20-M25 — "Other joint disorders" within Chapter 13 of the ICD-10-CM Tabular List.

What are the sub-codes of M21.2?

M21.2 has 1918 sub-code(s) that provide more specific detail: A00, A01, A02, A03, A04 and more.

When should I use M21.2?

Use M21.2 when the patients documented diagnosis matches "Flexion deformity" 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 Flexion deformity?

The ICD-10-CM code for Flexion deformity is M21.2.

Can M21.2 be used for primary diagnosis?

No, M21.2 is non-billable. Use a more specific sub-code for primary diagnosis billing.

What chapter is M21.2 in?

M21.2 is in Chapter 13 of the ICD-10-CM Tabular List.

Is M21.2 valid for 2026?

Yes, M21.2 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.

See Also

← PreviousM21.179Varus deformity, not elsewhere classified, unspecified ankleNext →M21.20Flexion deformity, unspecified site
Code Details
M21.2
Flexion deformity
Non-Billable / Non-Specific Code
13 — Diseases of the musculoskeletal system and connective tissue (M00-M99)
M20-M25 — Other joint disorders
2026 ICD-10-CM