R79.1 ICD-10-CM Code: Abnormal coagulation profile

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for R79.1 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2026Effective: October 1, 2025

Notes without a marker are published on R79.1 itself; “inherited from” names the category or block whose note applies here.

This page already reflects the FY2027 tabular note taking effect October 1, 2026.

Coder workflow for R79.1

MedCoder structured workflow — derived from this code’s own official record

Before you code R79.1

1. Check whether an established diagnosis that explains this sign or symptom is documented. If one is, review whether the documented diagnosis changes the coding pathway: a symptom that is integral to a confirmed diagnosis is not reported separately, while one not routinely associated with it may be. Signs and symptoms are reported when no definitive diagnosis is established (Guidelines I.B.4, I.B.5, I.B.6, I.C.18.b).

   Guide: Symptom code vs confirmed diagnosis →

2. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with R79.1. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).

   See the official tabular notes

Choose the right path

1. Is an established diagnosis that explains this sign or symptom documented?
   Yes → Review whether the documented diagnosis changes the coding pathway: a symptom integral to it is not reported separately.
   No → Continue — the sign or symptom code stands when no definitive diagnosis is established.
2. Does the documentation support a condition named in R79.1’s Excludes1 note?
   Yes → Do not simply proceed: review the excluded code. Both are reported only when the record shows the two conditions are unrelated.
   No → Continue.

   ReviewD68, E79.0, E16.2, E75

Consider R79.1. Then work the Use Additional Code note, and confirm the code is valid for the date of service in the Verify section.

Documentation check

The provider’s diagnostic statement

Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).

The conditions the Use Additional Code note names

Reported with this code when documented; a conditional instruction (“if applicable”, “if known”) applies only when the record supports it.

Official instructions as workflow

• Excludes1 — check before selecting R79.1(7 notes)

  Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with R79.1: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

  CompareD68, E79.0, E16.2, E75

  See the official tabular notes · Guidelines I.A.12.a

• Excludes2 — not part of R79.1(9 notes)

  Coding workflow: The conditions named in this note are not included in R79.1. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

  CompareR73.9, O28, E78, D69

  See the official tabular notes · Guidelines I.A.12.b

• Use Additional Code — after identifying R79.1(1 note)

  Coding workflow: Check whether the documentation supports the additional code(s) the note names, and report them with R79.1 when it does. Where the instruction is conditional (“if applicable”, “if known”), it applies only when the record documents the condition.

  ReviewZ18

  See the official tabular notes · Guidelines I.A.13

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Indexed Clinical Terms (11)

Official source data — entries quoted as published, in the Index’s own lookup phrasing

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code. These are alphabetic-index entries shown as the Index writes them — lookup phrasing, not necessarily the wording of a final diagnosis.

• Abnormal, abnormality, abnormalities, bleeding time
• Abnormal, abnormality, abnormalities, chemistry, blood, PTT
• Abnormal, abnormality, abnormalities, coagulation, profile
• Abnormal, abnormality, abnormalities, coagulation, time
• Abnormal, abnormality, abnormalities, partial thromboplastin time (PTT)
• Abnormal, abnormality, abnormalities, prothrombin time (PT)
• Low, von Willebrand factor
• Prolonged, prolongation (of), bleeding (time) (idiopathic)
• Prolonged, prolongation (of), coagulation (time)
• Prolonged, prolongation (of), partial thromboplastin time (PTT)
• Prolonged, prolongation (of), prothrombin time

Don’t confuse R79.1 with…

MedCoder analysis — pairs from this code’s official notes, distinctions written by MedCoder

The codes most likely to be picked instead of R79.1 — named in its own official notes, or sharing its laterality or encounter family — with what separates them and which documentation moves the case. Each links to the full comparison.

• D68— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of coagulation defects moves the case to D68; the two are not reported together unless documented as unrelated.

  Full comparison: R79.1 vs D68 →

• E79.0— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of asymptomatic hyperuricemia moves the case to E79.0; the two are not reported together unless documented as unrelated.

  Full comparison: R79.1 vs E79.0 →

• E16.2— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of hypoglycemia NOS moves the case to E16.2; the two are not reported together unless documented as unrelated.

  Full comparison: R79.1 vs E16.2 →

• P70.3— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of neonatal hypoglycemia moves the case to P70.3; the two are not reported together unless documented as unrelated.

  Full comparison: R79.1 vs P70.3 →

• P70.4— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of neonatal hypoglycemia moves the case to P70.4; the two are not reported together unless documented as unrelated.

  Full comparison: R79.1 vs P70.4 →

• E70— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of specific findings indicating disorder of amino-acid metabolism moves the case to E70; the two are not reported together unless documented as unrelated.

  Full comparison: R79.1 vs E70 →

Relationships are read from this code's own official notes, its laterality siblings and its encounter family; the wording of each distinction is MedCoder editorial, and the documentation named in each “what moves you there” line is the official note phrase or sibling title itself. Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a.

Decision Points

The directives on this code's own record, as a pre-claim checklist.

1. 1 Use Additional Code instruction — report the named additional code(s) when the documentation supports them. See the Use Additional Code notes
2. 7 Excludes1 entries — codes named there are generally not reported together with this code (Guidelines I.A.12.a). See the Excludes1 notes
3. 9 Excludes2 entries — those conditions are not part of this code and may be reported additionally when documented. See the Excludes2 notes

Checklist rows are derived from this code's own official directives; the wording of each check is MedCoder editorial. The official notes themselves are in the sections each row links to.

Verify Before Coding

• No Medicare Code Editor or MS-DRG Definitions Manual restrictions apply to this code.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder structured relationships — computed from published CMS and AHRQ datasets

Other codes that name R79.1 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 1 Excludes1 note: D68 — Other coagulation defects.

These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.

Referenced by 8 Excludes2 notes: R83 — Abnormal findings in cerebrospinal fluid (via R79.-), R83-R89 — Abnormal findings on examination of other body fluids, substances and tissues, without diagnosis (R83-R89) (via R79.-), R84 — Abnormal findings in specimens from respiratory organs and thorax (via R79.-), R85 — Abnormal findings in specimens from digestive organs and abdominal cavity (via R79.-), R86 — Abnormal findings in specimens from male genital organs (via R79.-), R87 — Abnormal findings in specimens from female genital organs (via R79.-), R88 — Abnormal findings in other body fluids and substances (via R79.-), R89 — Abnormal findings in specimens from other organs, systems and tissues (via R79.-).

These codes’ tabular lists name this diagnosis as distinct — both may be reported when both are documented.

MS-DRG Grouper Relationships (FY2026)

Potential MS-DRG participation — not a DRG assignment.

FY2026 MS-DRG: not on the CMS CC/MCC list — as a secondary diagnosis this code does not change MS-DRG severity for that release.

Named in the grouper logic of 2 MS-DRGs: DRG 947 (MDC 23), DRG 948 (MDC 23).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):SYM017 — Abnormal findings without diagnosis (default).

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Abnormal findings without diagnosis).

R77.1 — Abnormality of globulin, R77.2 — Abnormality of alphafetoprotein, R77.8 — Other specified abnormalities of plasma proteins, R77.9 — Abnormality of plasma protein, unspecified, R78.71 — Abnormal lead level in blood, R78.79 — Finding of abnormal level of heavy metals in blood, R78.81 — Bacteremia, R78.89 — Finding of other specified substances, not normally found in blood, R78.9 — Finding of unspecified substance, not normally found in blood, R79.0 — Abnormal level of blood mineral, R79.81 — Abnormal blood-gas level, R79.82 — Elevated C-reactive protein (CRP), R79.83 — Abnormal findings of blood amino-acid level, R79.89 — Other specified abnormal findings of blood chemistry, R79.9 — Abnormal finding of blood chemistry, unspecified, R81 — Glycosuria, R83.0 — Abnormal level of enzymes in cerebrospinal fluid, R83.1 — Abnormal level of hormones in cerebrospinal fluid, R83.2 — Abnormal level of other drugs, medicaments and biological substances in cerebrospinal fluid, R83.3 — Abnormal level of substances chiefly nonmedicinal as to source in cerebrospinal fluid, +183 more

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main terms “Abnormal, abnormality, abnormalities”, “Low”; these codes share that main term but sit in a different category of the Tabular List.

R76.81 — Abnormal rheumatoid factor and anti-citrullinated protein antibody without rheumatoid arthritis (anti-CCP), R76.89 — Other specified abnormal immunological findings in serum (immunological findings, in serum, specified NEC), R76.9 — Abnormal immunological finding in serum, unspecified (immunological findings, in serum), R77.0 — Abnormality of albumin (albumin), R77.1 — Abnormality of globulin (globulin), R77.2 — Abnormality of alphafetoprotein (alphafetoprotein), R77.8 — Other specified abnormalities of plasma proteins (plasma, protein, specified NEC), R77.9 — Abnormality of plasma protein, unspecified (plasma, protein), R78.89 — Finding of other specified substances, not normally found in blood (blood level, lithium), R78.9 — Finding of unspecified substance, not normally found in blood (toxicology), R81 — Glycosuria (urine, glucose), R82.0 — Chyluria (urine, fat), R82.1 — Myoglobinuria (urine, myoglobin), R82.2 — Biliuria (urine, bile), R82.3 — Hemoglobinuria (urine, hemoglobin), R82.4 — Acetonuria (urine, ketones), R82.5 — Elevated urine levels of drugs, medicaments and biological substances (urine, drugs), R82.6 — Abnormal urine levels of substances chiefly nonmedicinal as to source (urine, heavy metals), R82.79 — Other abnormal findings on microbiological examination of urine (urine, positive culture), R82.89 — Other abnormal findings on cytological and histological examination of urine (urine, cytological examination), +267 more

Lab tests where this diagnosis supports Medicare coverage (NCD)

Medicare's National Coverage Determination (NCD) program lists this diagnosis as medical justification for these lab tests.

Fecal Occult Blood Test (FOBT), Partial Thromboplastin Time (PTT) Test, Prothrombin Time Test and INR (PT/INR)

Contextual Map

Every relationship of R79.1 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run R79.1 with these 11 related codes in Claim Check

Hierarchy

• R00-R99 — Chapter 18: Symptoms, Signs and Abnormal Clinical and Laboratory Findings, Not Elsewhere Classified (R00-R99) (R00-R99)[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• R70-R79 — Abnormal findings on examination of blood, without diagnosis[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026

Excludes1

• D68 — Other coagulation defects[Excludes1]: “coagulation defects (D68.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Excludes2

• E86 — Volume depletion[Excludes2]: “abnormality of fluid, electrolyte or acid-base balance (E86-E87)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• E87 — Other disorders of fluid, electrolyte and acid-base balance[Excludes2]: “abnormality of fluid, electrolyte or acid-base balance (E86-E87)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Referenced by Excludes1 notes

• D68 — Other coagulation defects[Excludes1]: “abnormal coagulation profile NOS (R79.1)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Referenced by Excludes2 notes

• R83 — Abnormal findings in cerebrospinal fluid[Excludes2](via R79.-): “abnormal findings on examination of blood, without diagnosis (R70-R79)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• R83-R89 — Abnormal findings on examination of other body fluids, substances and tissues, without diagnosis (R83-R89)[Excludes2](via R79.-): “abnormal findings on examination of blood, without diagnosis (R70-R79)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• R84 — Abnormal findings in specimens from respiratory organs and thorax[Excludes2](via R79.-): “abnormal findings on examination of blood, without diagnosis (R70-R79)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• R85 — Abnormal findings in specimens from digestive organs and abdominal cavity[Excludes2](via R79.-): “abnormal findings on examination of blood, without diagnosis (R70-R79)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• R86 — Abnormal findings in specimens from male genital organs[Excludes2](via R79.-): “abnormal findings on examination of blood, without diagnosis (R70-R79)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• R87 — Abnormal findings in specimens from female genital organs[Excludes2](via R79.-): “abnormal findings on examination of blood, without diagnosis (R70-R79)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• R88 — Abnormal findings in other body fluids and substances[Excludes2](via R79.-): “abnormal findings on examination of blood, without diagnosis (R70-R79)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• R89 — Abnormal findings in specimens from other organs, systems and tissues[Excludes2](via R79.-): “abnormal findings on examination of blood, without diagnosis (R70-R79)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Clinical classification (CCSR)

• SYM017 — Abnormal findings without diagnosis[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)

MS-DRG Grouper

• DRG 947 — SIGNS AND SYMPTOMS WITH MCC[MS-DRG]: “SIGNS AND SYMPTOMS WITH MCC (MDC 23)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
• DRG 948 — SIGNS AND SYMPTOMS WITHOUT MCC[MS-DRG]: “SIGNS AND SYMPTOMS WITHOUT MCC (MDC 23)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026

MDC crossing

• MDC 23 — Factors Influencing Health Status and Other Contacts with Health Services[MDC crossing]: “Factors Influencing Health Status and Other Contacts with Health Services — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 1,235 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2026

Index entries (11)

• Abnormal, abnormality, abnormalities, bleeding time[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
• Abnormal, abnormality, abnormalities, chemistry, blood, PTT[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
• Abnormal, abnormality, abnormalities, coagulation, profile[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
• Abnormal, abnormality, abnormalities, coagulation, time[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
• Abnormal, abnormality, abnormalities, partial thromboplastin time (PTT)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
• Abnormal, abnormality, abnormalities, prothrombin time (PT)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
• Low, von Willebrand factor[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
• Prolonged, prolongation (of), bleeding (time) (idiopathic)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
• and 3 more

Nearest codes

• R79 — Other abnormal findings of blood chemistry[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• R79.0 — Abnormal level of blood mineral[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• R79.8 — Other specified abnormal findings of blood chemistry[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• R79.81 — Abnormal blood-gas level[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• R79.82 — Elevated C-reactive protein (CRP)[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• R79.83 — Abnormal findings of blood amino-acid level[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• R79.89 — Other specified abnormal findings of blood chemistry[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• R79.9 — Abnormal finding of blood chemistry, unspecified[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026

Change history (3)

• FY2027 — Excludes2 note will be added[Change history]— CMS release files (code change ledger) · icd10cm-fy2027
• and 2 more

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data

CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page

Claim edits Official source data

CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page

Inpatient payment groups Official source data

CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v43 Release, file and checksum · Publisher’s page

Change history and date-of-service validity Official source data

CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page

Comparisons, relationships and the contextual map MedCoder structured relationship

Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears

Summary and FAQ answers MedCoder explanation

Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Nearest Codes in This Family

Official ICD-10-CM classifications closest to R79.1 in its code family, with their registry titles.

• R79 — Other abnormal findings of blood chemistry
• R79.0 — Abnormal level of blood mineral
• R79.8 — Other specified abnormal findings of blood chemistry
• R79.81 — Abnormal blood-gas level
• R79.82 — Elevated C-reactive protein (CRP)
• R79.83 — Abnormal findings of blood amino-acid level
• R79.89 — Other specified abnormal findings of blood chemistry
• R79.9 — Abnormal finding of blood chemistry, unspecified

View all codes in the R79 family