ICD-10 Coding Guides
Free, fact-checked coding guides for medical coders and billing professionals. Each guide covers the most common coding questions, documentation requirements, and mistakes for its topic.
ICD-10 Code E11.9 — Type 2 Diabetes Without Complications
When to use E11.9 vs related codes, insulin coding with Z79.4, CKD staging combinations, and the five most common diabetes coding mistakes.
CirculatoryICD-10 Code I10 — Essential Hypertension Complete Guide
Controlled vs uncontrolled hypertension, I10 vs I11/I12/I13 combination codes, resistant hypertension I1A.0, and the combination code rule coders get wrong most often.
Mental HealthICD-10 Codes for Depression — F32 and F33 Guide
Single vs recurrent episode, F32.9 vs F32.A, severity specifiers, reactive depression, bipolar excludes notes, and why F38 does not exist in ICD-10-CM.
Z CodesICD-10 Personal History Codes — Z85, Z86, Z87 Guide
When to use history codes vs active diagnosis codes, history of stroke, cancer, hepatitis C, nicotine dependence, sequencing rules, and the difference between personal and family history codes.
SymptomsICD-10 Codes for Abdominal Pain — R10 Complete Guide
R10.9 vs R10.84, location-specific codes for every quadrant, FY2026 new flank pain codes R10.A0–A3, why R10.2 is no longer valid, and when not to use a symptom code at all.
GenitourinaryICD-10 Code for UTI — N39.0 Complete Coding Guide
N39.0 vs cystitis N30.00 vs pyelonephritis N10, hematuria distinction, organism codes B96.20, recurrent UTI with Z87.440, and why N39.0 is wrong when the site is documented.
CirculatoryICD-10 Code for Stroke — I63.9, Z86.73 & I69 Guide
I63.9 acute ischemic stroke vs Z86.73 history without deficits vs I69.x sequelae with deficits, TIA coding, dominant/nondominant side, and the hemorrhagic-stroke code family.
MusculoskeletalICD-10 Code for Back Pain — M54.50, M54.51, M54.59 Guide
Why M54.5 is invalid and auto-denies, M54.50 vs M54.51 vertebrogenic vs M54.59, sciatica and radiculopathy code families, and when a disc disorder replaces the symptom code.
MusculoskeletalICD-10 Codes for Knee Pain — M25.561, M25.562, M17 Guide
M25.561 vs M25.562 vs M25.569, bilateral knee pain with no combined code, the complete M17 osteoarthritis family, and when a confirmed diagnosis replaces the pain code.
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