Reviewed by certified coders + a maternal-fetal medicine physician / Updated for 2026
OB Coding Guide
OB Coding Guide
obcodingguide.com/codes/59000/
Clinical review: Sina Haeri, MD, MHSA (MFM) · Coder review pending · Drafted July 2026
59000 Procedure
CPT 59000

CPT 59000: Amniocentesis, DiagnosticAmniocentesis, Diagnostic

The short answer

Use 59000 for a diagnostic amniocentesis: inserting a needle through the abdomen into the amniotic sac to withdraw fluid for testing, most often fetal karyotype or microarray after an abnormal screen. The ultrasound guidance used to place the needle bills separately as 76946, and the whole procedure sits outside the global OB package.

Source: NCCISource: CMS MPFS 2026Source: ACOG

When to use 59000

Report 59000 when fluid is withdrawn for diagnostic purposes: confirming an abnormal NIPT or serum screen result, evaluating an ultrasound anomaly, testing for fetal infection, or assessing fetal lung maturity. It covers the needle procedure itself. The imaging guidance is its own code (76946), and the laboratory analysis of the fluid (karyotype, microarray, amnio fluid studies) is billed by the lab under its own codes. Therapeutic amnioreduction, draining fluid to treat polyhydramnios, is a different code (59001), not this one.

What 59000 includes vs what bills separately
59000 · The procedure
  • Needle placement and fluid withdrawal
  • Routine pre- and post-procedure care same day
  • Diagnostic intent (confirming a screen, anomaly workup, infection)
  • One unit per gestational sac entered
Billed separately
  • 76946, the ultrasound guidance for needle placement
  • Lab analysis of the fluid (karyotype, microarray, other studies)
  • Rh immune globulin for Rh-negative patients (product plus admin)
  • Distinct E/M or consult that led to the decision, when separately documented

Documentation checklist

Amniocentesis claims are simple when the note covers the indication, the guidance, and the counseling. Denials come from gaps in those three.

✓ Indication documented (abnormal screening result, ultrasound finding, infection concern, lung maturity)
✓ Informed consent covering the procedure's miscarriage risk
✓ Procedure note: gestational age, needle placement, fluid volume withdrawn, fetal heart activity confirmed after
✓ Ultrasound guidance documented with an image saved, supporting the separate 76946 charge
✓ Rh status checked, with immune globulin given and documented for Rh-negative patients
✓ For multiples, which sac was entered, per sac

Global package rules

Amniocentesis is not part of the global obstetric package. 59000 bills separately from 59400 whenever it is performed, because the global package covers routine antepartum care and diagnostic procedures are by definition not routine. Bill the guidance code 76946 on the same claim; NCCI does not bundle it into 59000 when the guidance is documented with a saved image. If a problem visit on the same day led to the decision to proceed, that E/M can bill with modifier 25 when it is separately documented. NCCI

Reimbursement

2026 · national Medicare averages
ComponentWork RVUTotal RVU2026 rate
59000Global1.273.58$119.58

National amounts under the 2026 Medicare Physician Fee Schedule (non-facility total RVU x $33.4009 conversion factor, no locality/MAC adjustment). Commercial and Medicaid rates differ. Verify current values with your MAC before billing.

Common denials

CO-97 Guidance code 76946 bundled into the procedure
Why it happens
The payer's edit treated the ultrasound guidance as included in the amniocentesis, or the guidance was billed without documentation.
How to fix
Appeal with the procedure note and the saved guidance image. 76946 is separately reportable with 59000 under NCCI; cite the edit table showing no bundling between the pair.
Source: NCCI
CO-50 Not medically necessary
Why it happens
The claim carried a routine pregnancy diagnosis instead of the finding that prompted the procedure.
How to fix
Resubmit with the indication as primary: the abnormal screen result, the ultrasound anomaly, or the specific condition under investigation. A diagnostic procedure needs a diagnostic reason on the claim.
Source: ACOG
CO-97 Bundled into the global OB package
Why it happens
The payer swept the procedure into the global package paid to the same practice.
How to fix
Appeal stating that diagnostic amniocentesis is outside the global package, which covers routine antepartum care only. This is a well-established carve-out; most payers reverse on first-level appeal.
Source: NCCI
CO-16 Missing or invalid information for multiple units
Why it happens
Two units of 59000 for a twin gestation billed without modifiers or sac-level documentation.
How to fix
Bill the second sac on its own line with modifier 59 or XS and document each needle entry separately. One sac tapped means one unit, regardless of the number of fetuses.
Source: CMS

FAQ

What is the CPT code description for 59000?
In plain language, 59000 covers a diagnostic amniocentesis: passing a thin needle through the abdominal wall into the amniotic sac and withdrawing fluid so it can be tested, typically for chromosome analysis after an abnormal screening result.
Is ultrasound guidance included in 59000?
No. Bill 76946 separately for the needle guidance. Document the guidance in the procedure note and save an image; that documentation is what wins the appeal if a payer bundles it.
Is amniocentesis part of the global OB package?
No. It is a diagnostic procedure and bills separately from 59400 even when the same practice provides all the global care.
How do I bill amniocentesis for twins?
Per sac entered, not per fetus. Two sacs tapped bills two units, the second with modifier 59 or XS and its own documentation. One shared or single sac entered is one unit.
Who bills for the karyotype or microarray on the fluid?
The laboratory that performs the analysis, under its own molecular or cytogenetic codes. 59000 pays the proceduralist for obtaining the specimen only.
What code applies when fluid is drained to treat polyhydramnios?
That is therapeutic amnioreduction, reported with 59001, not 59000. The distinction is intent: 59000 obtains a specimen for testing, 59001 removes volume as treatment.
CPT® is a registered trademark of the American Medical Association. Educational reference only, not billing, legal, or medical advice. Maintained by Ouma Health, a maternal-fetal telemedicine practice. Printed from obcodingguide.com, content current as of July 2026.