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Search medical codes and explore official coding references.
Search · Find a code or coding concept
- CodeE11.9
- Conditiondiabetes
- Combinationhypertension with heart failure
- ProcedureMRI brain
- ConceptExcludes1
ICD-10-CM, ICD-10-PCS and HCPCS Level II, by code or plain-language term — diagnoses, procedures, supplies, lab tests and coding concepts. Every result links its official instructions and sources. New to these terms? What these terms mean
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- CompareCompare codes →Understand the official differences between codes.Example: E11.9 vs E10.9
- Claim CheckCheck a code list →Review a list of codes against supported coding-rule checks.A coding check against supported CMS rules, not a payer adjudication
More resources
Every code set, rule and reference MedCoder holds, grouped by what it is.
Code sets and indexes
- ICD-10-CM
Diagnosis codes
- ICD-10-PCS
Inpatient procedure codes
- HCPCS Level II
Procedure, supply and drug codes
- MS-DRG
Inpatient payment groups
- HCPCS modifiers
Pricing and payment modifiers
- NDC Directory
FDA drug products
- Clinical labs
Reference ranges
- ICD-10 codes by condition
Grouped by AHRQ CCSR category
- Drugs & Chemicals index
Poisoning, adverse effect and underdosing codes
- External Causes index
Mechanism-of-injury codes (V00-Y99)
Rules and coverage
- Coding rules reference
What each supported CMS rule set checks, and its source release
- NCCI PTP
Supported CMS-derived procedure-to-procedure rules within MedCoder’s non-CPT scope.
- MUE
Supported published Medicare utilization-edit information within MedCoder’s non-CPT scope.
- Coverage policies
Policy research — not a coverage determination
- Inpatient grouping (MS-DRG)
Independent implementation; not CMS-certified or endorsed
Guides and history
- Coding guides
Scenario guides to Excludes1 vs Excludes2, 7th characters, sequencing, POA (present on admission) and more, verified against the official sources
- Coding questions
Real-world questions, answered from the official sources
- What a code page shows
Official notes, relationships, history and sources, on E11.9
- Change ledger
Every code added, deleted or revised, by release
Browse by chapter, section or group
ICD-10-CM is the largest code set here, so its chapters are listed in full. The other code sets index the same way on their own pages.
Other code setsHCPCS Level II by sectionICD-10-PCS by sectionMS-DRG by MDCAll code sets →
- Ch 1 · A00-B99Certain Infectious and Parasitic Diseases
- Ch 2 · C00-D49Neoplasms
- Ch 3 · D50-D89Diseases of the Blood and Blood-forming Organs and Certain Disorders Involving the Immune Mechanism
- Ch 4 · E00-E89Endocrine, Nutritional and Metabolic Diseases
- Ch 5 · F01-F99Mental, Behavioral and Neurodevelopmental Disorders
- Ch 6 · G00-G99Diseases of the Nervous System
- Ch 7 · H00-H59Diseases of the Eye and Adnexa
- Ch 8 · H60-H95Diseases of the Ear and Mastoid Process
- Ch 9 · I00-I99Diseases of the Circulatory System
- Ch 10 · J00-J99Diseases of the Respiratory System
- Ch 11 · K00-K95Diseases of the Digestive System
- Ch 12 · L00-L99Diseases of the Skin and Subcutaneous Tissue
- Ch 13 · M00-M99Diseases of the Musculoskeletal System and Connective Tissue
- Ch 14 · N00-N99Diseases of the Genitourinary System
- Ch 15 · O00-O9APregnancy, Childbirth and the Puerperium
- Ch 16 · P00-P96Certain Conditions Originating in the Perinatal Period
- Ch 17 · Q00-QA1Congenital Malformations, Deformations and Chromosomal Abnormalities
- Ch 18 · R00-R99Symptoms, Signs and Abnormal Clinical and Laboratory Findings, Not Elsewhere Classified
- Ch 19 · S00-T88Injury, Poisoning and Certain Other Consequences of External Causes
- Ch 20 · V00-Y99External Causes of Morbidity
- Ch 21 · Z00-Z99Factors Influencing Health Status and Contact with Health Services
- Ch 22 · U00-U85Codes for special purposes
About MedCoder
Official-source coding rules — not AI guesses.
Every code, note and rule is quoted from the published CMS, CDC, FDA or AHRQ file and labelled with its release. Checks are deterministic rules over that data. MedCoder generates no coding facts and does not predict what a payer will do.
MedCoder is an independent reference built on CMS and other federal source data. It is not certified, approved, endorsed, sponsored or operated by CMS.
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- Official-source data
- Version-aware
- Traceable to source
- Deterministic rules
- Not AI guesses
- CPT not reproduced
ICD-10-CM · Current: FY2027, From October 1, 2026 · Next release: not yet published
Current data releases:ICD-10-CM FY2027 · ICD-10-PCS FY2027 · HCPCS October 2026 · MS-DRG v44 · Medicare Code Editor v44.0 · NCCI PTP Q4 2026 · MUE Q4 2026 · NCD code lists 2026-01 · LCD export September 28, 2026 · All releases and sources
Data sources and release status → How MedCoder verifies its implementation →
What MedCoder does not do
- Supported HCPCS Level II subset; CPT content excluded
- MedCoder’s NCCI/PTP and MUE displays are a supported subset, not complete NCCI or MUE tables. The absence of an edit in MedCoder must not be interpreted as evidence that no CPT edit exists.
- LCD identified ≠ coverage determination
- Finding an LCD means “review this policy,” not “this service is covered.” Failure to identify an LCD does not mean that the service is covered.
- Code-list match ≠ coverage determination
- A matching NCD code list does not by itself establish coverage. Absence of a matching code does not by itself establish non-coverage.
- Independent implementation; not CMS-certified or endorsed
- MedCoder’s MS-DRG grouping independently implements CMS-published logic and tables, and is compared against CMS’s grouper software on a stated verification corpus. A grouping does not determine reimbursement or payment.
- No issue found ≠ approved, covered or payable
- No issue found does not mean approved, covered, or payable. It means no issue was identified by the supported MedCoder checks performed for the information provided.
- Data unavailable = insufficient supported source data
- Not evidence that no rule exists, that a code is allowed, or that a service is covered.