CBCS (NHA) Cheat Sheet.
The night-before summary, built like the exam.

CBCS (NHA) — Exam Snapshot

• Questions: 100 scored
• Time limit: 180 minutes (3 hours)
• Passing score: 390 scaled or higher
• Cost: $129
• Pace target: ~1.8 min/question — leave time to flag & revisit

Must-Know Code Sets

• ICD-10-CM — diagnoses (why the visit happened). 3–7 characters; 1st char is a letter; laterality & encounter (7th char A/D/S).
• CPT — physician/outpatient procedures & services. 5-digit numeric (Category I), plus Category II (tracking, ends in F) and III (emerging tech, ends in T).
• HCPCS Level II — supplies, drugs, DME, ambulance (alphanumeric, letter + 4 digits).
• Modifiers — 2 characters appended to CPT/HCPCS to add detail (e.g., -25 significant separate E/M, -59 distinct procedure, -50 bilateral, -RT/-LT side).

Claim Forms — Memorize the Pairing

• CMS-1500 — physician / non-institutional (professional) claims. Electronic equivalent: 837P.
• UB-04 (CMS-1450) — hospital / institutional claims. Electronic equivalent: 837I.
• NPI — 10-digit provider identifier required on claims.

HIPAA Transactions (X12)

• 270/271 — eligibility inquiry / response
• 276/277 — claim status inquiry / response
• 837 — claim submission · 835 — remittance advice / ERA (payment)
• Clean claim = no defects, no extra info needed → fastest payment.

Payer & Reimbursement Rules

• Medicare Part A hospital/inpatient · Part B outpatient/physician · Part C Advantage · Part D drugs.
• Medigap supplements Medicare; Medicaid is state/federal, always payer of last resort.
• Coordination of Benefits (COB): primary pays first; Birthday Rule for a child's dual coverage — parent whose birthday (month/day) is earlier in the year is primary.
• ABN (Advance Beneficiary Notice) — notify Medicare patient of likely non-coverage before service.

Money Formulas

• Allowed amount − Paid amount = Patient responsibility (deductible + copay + coinsurance).
• Coinsurance: patient % of allowed amount (e.g., 80/20 → patient owes 20%).
• Copay = fixed $ per visit; Deductible = paid before insurer contributes.
• Write-off / adjustment = billed − allowed (contractual, not billed to patient for par providers).
• Aging buckets: 0–30, 31–60, 61–90, 90+ days for A/R follow-up.

Compliance Landmines

• Upcoding (higher-paying code than performed) and unbundling (separate codes instead of a bundle) = fraud.
• Fraud = intentional; abuse = practices inconsistent with sound billing. NCCI edits catch improper code pairs.
• HIPAA: minimum necessary; PHI protected; TPO (Treatment, Payment, Operations) allowed without extra authorization.

Fastest Wins on Exam Day

• Diagnosis code first justifies the procedure — check medical necessity.
• Match form to setting: professional → CMS-1500/837P, institutional → UB-04/837I.
• Read the 835/ERA to reconcile, appeal denials, and post payments.