CPT Code 83918Complete Billing & Coding Guide (2026)Organic acids total quant
About CPT 83918
CPT 83918 is a Current Procedural Terminology code in the Pathology/Lab category maintained by the American Medical Association. The CMS short descriptor reads "Organic acids total quant". For the full AMA long descriptor and clinical guidance, refer to the current CPT code manual.
Documentation specificity, correct ICD-10 linkage, and modifier accuracy determine whether 83918 pays cleanly or triggers a denial. Verify CMS National Physician Fee Schedule status, applicable Medicare LCDs, and any payer-specific medical policies before submission.
83918 has 2 NCCI bundling edit pairs documented. Run your scrubber against the NCCI quarterly update before submission. When clinically warranted, use modifier 59 or the X-modifiers (XE, XS, XP, XU) to bypass an indicator-1 edit, with chart documentation supporting the distinct service.
Code Properties
RVU Breakdown
Every CPT code’s Medicare payment is calculated from three Relative Value Unit components: physician work, practice expense, and malpractice. Together they multiply by the conversion factor to produce the payment amount.
Payment = Total RVU × Conversion Factor ($33.4009) × Geographic Adjustment (GPCI). National averages shown. Actual payment varies by locality.
NCCI Bundling Edits
2 pairsThese codes trigger National Correct Coding Initiative edits when billed with 83918. An indicator of 0 means the pair cannot be unbundled. Indicator 1 means modifier 59 or X-modifiers may allow separate billing with supporting documentation.
Billing 83918 alongside a bundled code without the correct modifier generates CARC 97 denials. Payers often flag these as audit risks. Document medical necessity for the separate service and apply modifier 59 or the appropriate X-modifier (XE, XS, XP, XU) only when clinically justified.
More extensive procedure
CPT Manual or CMS manual coding instruction
Bundling denials on 83918 are recoverable when the edit indicator is 1 and the chart documents a distinct, separately identifiable service. Our coders verify the indicator and pick the precise X-modifier (XE, XS, XP, XU) instead of defaulting to modifier 59.
Applicable Modifiers
Modifiers commonly paired with 83918 based on its category. Apply only when the clinical circumstance warrants. Incorrect modifier use is a top audit target.
Component split modifiers (26 professional, TC technical) are the most under-applied modifiers in diagnostic billing. Practices that bill global on services where they only provided the read silently invite refund requests. We split components correctly at submission.
Find the revenue leakage in your 83918 claims.
Wrong modifier, missing documentation, bundling without justification, stale ICD-10 linkage: these are the silent revenue killers on Pathology/Lab claims. Our AAPC-certified team audits your last 90 days of 83918 claims, surfaces the recoverable dollars, and appeals them. Free, no obligation.
Losing revenue on CPT 83918? We’ll find it.
We audit your last 90 days of claims and surface the recoverable revenue leakage: wrong modifiers, missed bundling appeals, ICD-10 specificity gaps. AAPC-certified coders. 2.49% of collections. No setup fees.
Get Your Free Billing Assessment
Free audit, no obligation. We'll review your billing and show you exactly where revenue is leaking.
Related CPT Codes
Codes in the same family as 83918
Everything about CPT 83918
What does CPT code 83918 cover?
CPT 83918 is a Current Procedural Terminology code in the Pathology/Lab category maintained by the American Medical Association. The CMS short descriptor reads "Organic acids total quant". For the full AMA long descriptor and clinical guidance, refer to the current CPT code manual.
What is the Medicare payment for CPT 83918?
The national average Medicare payment for CPT 83918 is approximately $0 in a non-facility setting and $0 in a facility setting. Actual payment varies by locality based on GPCI adjustments. Total RVU is 0 with a conversion factor of $33.4009.
What is the global period for CPT 83918?
CPT 83918 has no global period (indicator XXX). There are no post-operative day restrictions tied to this code. Refer to CMS National Physician Fee Schedule rules and any applicable NCCI edits when billing on the same date as other services.
What codes bundle with CPT 83918?
CPT 83918 has NCCI Procedure-to-Procedure edits with 2+ codes including 83919, 96523. Modifier indicator 0 means the edit cannot be bypassed. Indicator 1 means modifier 59 or X-modifiers may allow separate billing with documentation.
CPT codes and descriptions are copyright of the American Medical Association. RVU values reflect current CMS publications. Actual payment varies by locality. Commercial payer rates vary by contract.
Free 90-Day AR Recovery Audit
We audit your last 90 days of claims and surface the revenue leakage: wrong modifiers, missed bundling appeals, ICD-10 specificity gaps. AAPC-certified coders. 2.49% of collections. No setup fees.