S66.0
Non-Billable

Injury of long flexor muscle, fascia and tendon of thumb at wrist and hand level

Non-Billable / Non-Specific Code

What is Injury of long flexor muscle, fascia and tendon of thumb at wrist and hand level?

ICD-10-CM S66.0 is the diagnosis code for Injury of long flexor muscle, fascia and tendon of thumb at wrist and hand level. This code falls under the section "Injuries to the wrist, hand and fingers" within Chapter 19 — Injury, poisoning and certain other consequences of external causes (S00-T88). 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 S66.0

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 S66.0 sits in the ICD-10-CM classification helps ensure proper coding:

Current CodeS66.0 — Injury of long flexor muscle, fascia and tendon of thumb at wrist and hand level
Sub-Codes (1918)
A00A01A02A03A04A05A06A07A08A09A15A17A18A19A20A21A22A23A24A25A26A27A28A30A31A32A33A34A35A36A37A38A39A40A41A42A43A44A46A48A49A50A51A52A53A54A55A56A57A58A59A60A63A64A65A66A67A68A69A70A71A74A75A77A78A79A80A81A82A83A84A85A86A87A88A89A90A91A92A93A94A95A96A98A99B00B01B02B03B04B05B06B07B08B09B10B15B16B17B18B19B20B25B26B27B30B33B34B35B36B37B38B39B40B41B42B43B44B45B46B47B48B49B50B51B52B53B54B55B56B57B58B59B60B64B65B66B67B68B69B70B71B72B73B74B75B76B77B78B79B80B81B82B83B85B86B87B88B89B90B91B92B94B95B96B97B99C00C01C02C03C04C05C06C07C08C09C10C11C12C13C14C15C16C17C18C19C20C21C22C23C24C25C26C30C31C32C33C34C37C38C39C40C41C43C44C45C46C47C48C49C4AC50C51C52C53C54C55C56C57C58C60C61C62C63C64C65C66C67C68C69C70C71C72C73C74C75C76C77C78C79C7AC7BC80C81C82C83C84C85C86C88C90C91C92C93C94C95C96D00D01D02D03D04D05D06D07D09D10D11D12D13D14D15D16D17D18D19D20D21D22D23D24D25D26D27D28D29D30D31D32D33D34D35D36D37D38D39D3AD40D41D42D43D44D45D46D47D48D49D50D51D52D53D55D56D57D58D59D60D61D62D63D64D65D66D67D68D69D70D71D72D73D74D75D76D77D78D80D81D82D83D84D86D89E00E01E02E03E04E05E06E07E08E09E10E11E13E15E16E20E21E22E23E24E25E26E27E28E29E30E31E32E34E35E36E40E41E42E43E44E45E46E50E51E52E53E54E55E56E58E59E60E61E63E64E65E66E67E68E70E71E72E73E74E75E76E77E78E79E80E83E84E85E86E87E88E89F01F02F03F04F05F06F07F09F10F11F12F13F14F15F16F17F18F19F20F21F22F23F24F25F28F29F30F31F32F33F34F39F40F41F42F43F44F45F48F50F51F52F53F54F55F59F60F63F64F65F66F68F69F70F71F72F73F78F79F80F81F82F84F88F89F90F91F93F94F95F98F99G00G01G02G03G04G05G06G07G08G09G10G11G12G13G14G20G21G23G24G25G26G30G31G32G35G36G37G40G43G44G45G46G47G50G51G52G53G54G55G56G57G58G59G60G61G62G63G64G65G70G71G72G73G80G81G82G83G89G90G91G92G93G94G95G96G97G98G99H00H01H02H04H05H10H11H15H16H17H18H20H21H22H25H26H27H28H30H31H32H33H34H35H36H40H42H43H44H46H47H49H50H51H52H53H54H55H57H59H60H61H62H65H66H67H68H69H70H71H72H73H74H75H80H81H82H83H90H91H92H93H94H95I00I01I02I05I06I07I08I09I10I11I12I13I15I16I1AI20I21I22I23I24I25I26I27I28I30I31I32I33I34I35I36I37I38I39I40I41I42I43I44I45I46I47I48I49I50I51I52I5AI60I61I62I63I65I66I67I68I69I70I71I72I73I74I75I76I77I78I79I80I81I82I83I85I86I87I88I89I95I96I97I99J00J01J02J03J04J05J06J09J10J11J12J13J14J15J16J17J18J20J21J22J30J31J32J33J34J35J36J37J38J39J40J41J42J43J44J45J47J4AJ60J61J62J63J64J65J66J67J68J69J70J80J81J82J84J85J86J90J91J92J93J94J95J96J98J99K00K01K02K03K04K05K06K08K09K11K12K13K14K20K21K22K23K25K26K27K28K29K30K31K35K36K37K38K40K41K42K43K44K45K46K50K51K52K55K56K57K58K59K60K61K62K63K64K65K66K67K68K70K71K72K73K74K75K76K77K80K81K82K83K85K86K87K90K91K92K94K95L00L01L02L03L04L05L08L10L11L12L13L14L20L21L22L23L24L25L26L27L28L29L30L40L41L42L43L44L45L49L50L51L52L53L54L55L56L57L58L59L60L62L63L64L65L66L67L68L70L71L72L73L74L75L76L80L81L82L83L84L85L86L87L88L89L90L91L92L93L94L95L97L98L99M00M01M02M04M05M06M07M08M10M11M12M13M14M15M16M17M18M19M1AM20M21M22M23M24M25M26M27M30M31M32M33M34M35M36M40M41M42M43M45M46M47M48M49M50M51M53M54M60M61M62M63M65M66M67M70M71M72M75M76M77M79M80M81M83M84M85M86M87M88M89M90M91M92M93M94M95M96M97M99N00N01N02N03N04N05N06N07N08N10N11N12N13N14N15N16N17N18N19N20N21N22N23N25N26N27N28N29N30N31N32N33N34N35N36N37N39N40N41N42N43N44N45N46N47N48N49N50N51N52N53N60N61N62N63N64N65N70N71N72N73N74N75N76N77N80N81N82N83N84N85N86N87N88N89N90N91N92N93N94N95N96N97N98N99O00O01O02O03O04O07O08O09O10O11O12O13O14O15O16O20O21O22O23O24O25O26O28O29O30O31O32O33O34O35O36O40O41O42O43O44O45O46O47O48O60O61O62O63O64O65O66O67O68O69O70O71O72O73O74O75O76O77O80O82O85O86O87O88O89O90O91O92O94O98O99O9AP00P01P02P03P04P05P07P08P09P10P11P12P13P14P15P19P22P23P24P25P26P27P28P29P35P36P37P38P39P50P51P52P53P54P55P56P57P58P59P60P61P70P71P72P74P76P77P78P80P81P83P84P90P91P92P93P94P95P96Q00Q01Q02Q03Q04Q05Q06Q07Q10Q11Q12Q13Q14Q15Q16Q17Q18Q20Q21Q22Q23Q24Q25Q26Q27Q28Q30Q31Q32Q33Q34Q35Q36Q37Q38Q39Q40Q41Q42Q43Q44Q45Q50Q51Q52Q53Q54Q55Q56Q60Q61Q62Q63Q64Q65Q66Q67Q68Q69Q70Q71Q72Q73Q74Q75Q76Q77Q78Q79Q80Q81Q82Q83Q84Q85Q86Q87Q89Q90Q91Q92Q93Q95Q96Q97Q98Q99QA0R00R01R03R04R05R06R07R09R10R11R12R13R14R15R16R17R18R19R20R21R22R23R25R26R27R29R30R31R32R33R34R35R36R37R39R40R41R42R43R44R45R46R47R48R49R50R51R52R53R54R55R56R57R58R59R60R61R62R63R64R65R68R69R70R71R73R74R75R76R77R78R79R80R81R82R83R84R85R86R87R88R89R90R91R92R93R94R97R99S00S01S02S03S04S05S06S07S08S09S10S11S12S13S14S15S16S17S19S20S21S22S23S24S25S26S27S28S29S30S31S32S33S34S35S36S37S38S39S40S41S42S43S44S45S46S47S48S49S50S51S52S53S54S55S56S57S58S59S60S61S62S63S64S65S66S67S68S69S70S71S72S73S74S75S76S77S78S79S80S81S82S83S84S85S86S87S88S89S90S91S92S93S94S95S96S97S98S99T07T14T15T16T17T18T19T20T21T22T23T24T25T26T27T28T30T31T32T33T34T36T37T38T39T40T41T42T43T44T45T46T47T48T49T50T51T52T53T54T55T56T57T58T59T60T61T62T63T64T65T66T67T68T69T70T71T73T74T75T76T78T79T80T81T82T83T84T85T86T87T88U07U09V00V01V02V03V04V05V06V09V10V11V12V13V14V15V16V17V18V19V20V21V22V23V24V25V26V27V28V29V30V31V32V33V34V35V36V37V38V39V40V41V42V43V44V45V46V47V48V49V50V51V52V53V54V55V56V57V58V59V60V61V62V63V64V65V66V67V68V69V70V71V72V73V74V75V76V77V78V79V80V81V82V83V84V85V86V87V88V89V90V91V92V93V94V95V96V97V98V99W00W01W03W04W05W06W07W08W09W10W11W12W13W1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Sub-Codes 4 entries
S66.00Unspecified injury of long flexor muscle, fascia and tendon of thumb at wrist and hand levelNon-BillableS66.001Unspecified injury of long flexor muscle, fascia and tendon of right thumb at wrist and hand levelBillableS66.002Unspecified injury of long flexor muscle, fascia and tendon of left thumb at wrist and hand levelBillableS66.009Unspecified injury of long flexor muscle, fascia and tendon of unspecified thumb at wrist and hand levelBillableS66.01Strain of long flexor muscle, fascia and tendon of thumb at wrist and hand levelNon-BillableS66.011Strain of long flexor muscle, fascia and tendon of right thumb at wrist and hand levelBillableS66.012Strain of long flexor muscle, fascia and tendon of left thumb at wrist and hand levelBillableS66.019Strain of long flexor muscle, fascia and tendon of unspecified thumb at wrist and hand levelBillableS66.02Laceration of long flexor muscle, fascia and tendon of thumb at wrist and hand levelNon-BillableS66.021Laceration of long flexor muscle, fascia and tendon of right thumb at wrist and hand levelBillableS66.022Laceration of long flexor muscle, fascia and tendon of left thumb at wrist and hand levelBillableS66.029Laceration of long flexor muscle, fascia and tendon of unspecified thumb at wrist and hand levelBillableS66.09Other specified injury of long flexor muscle, fascia and tendon of thumb at wrist and hand levelNon-BillableS66.091Other specified injury of long flexor muscle, fascia and tendon of right thumb at wrist and hand levelBillableS66.092Other specified injury of long flexor muscle, fascia and tendon of left thumb at wrist and hand levelBillableS66.099Other specified injury of long flexor muscle, fascia and tendon of unspecified thumb at wrist and hand levelBillable
Related Codes

Frequently Asked Questions

Is S66.0 a billable ICD-10-CM code?

No, S66.0 is a non-billable/non-specific code. You should use a more specific sub-code for billing and reimbursement.

What does S66.0 mean?

S66.0 is the ICD-10-CM diagnosis code for "Injury of long flexor muscle, fascia and tendon of thumb at wrist and hand level". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.

What is the parent code of S66.0?

The parent code of S66.0 is S66 ("Injury of muscle, fascia and tendon at wrist and hand level"). S66.0 provides a more specific classification within this category.

What section is S66.0 in?

S66.0 is located in Section S60-S69 — "Injuries to the wrist, hand and fingers" within Chapter 19 of the ICD-10-CM Tabular List.

What are the sub-codes of S66.0?

S66.0 has 1918 sub-code(s) that provide more specific detail: A00, A01, A02, A03, A04 and more.

When should I use S66.0?

Use S66.0 when the patients documented diagnosis matches "Injury of long flexor muscle, fascia and tendon of thumb at wrist and hand level" 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 Injury of long flexor muscle, fascia and tendon of thumb at wrist and hand level?

The ICD-10-CM code for Injury of long flexor muscle, fascia and tendon of thumb at wrist and hand level is S66.0.

Can S66.0 be used for primary diagnosis?

No, S66.0 is non-billable. Use a more specific sub-code for primary diagnosis billing.

What chapter is S66.0 in?

S66.0 is in Chapter 19 of the ICD-10-CM Tabular List.

Is S66.0 valid for 2026?

Yes, S66.0 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.

See Also

← PreviousS66Injury of muscle, fascia and tendon at wrist and hand levelNext →S66.00Unspecified injury of long flexor muscle, fascia and tendon of thumb at wrist and hand level
Code Details
S66.0
Injury of long flexor muscle, fascia and tendon of thumb at wrist and hand level
Non-Billable / Non-Specific Code
19 — Injury, poisoning and certain other consequences of external causes (S00-T88)
S60-S69 — Injuries to the wrist, hand and fingers
2026 ICD-10-CM