Lab & pathology
85730 — Thromboplastin time, partial ; activated
A blood clotting test measuring partial thromboplastin time (PTT or aPTT) to evaluate the intrinsic clotting pathway, used to diagnose bleeding disorders and to monitor heparin therapy.
- Typical setting: Hospital lab, reference lab, doctor's office
- National avg charge (illustrative): $5–$15 Medicare allowed (CMS CLFS); $10–$45 commercial; varies by region
- Most-disputed reason: Confusing 85730 (PTT) with 85610 (PT) — both are clotting tests measuring different pathways; each requires separate documentation of clinical indication
What it means
What 85730 actually means
A blood clotting test measuring partial thromboplastin time (PTT or aPTT) to evaluate the intrinsic clotting pathway, used to diagnose bleeding disorders and to monitor heparin therapy. It is often ordered together with PT (85610) for a comprehensive coagulation workup.
Common errors with this code
What goes wrong on real bills.
Most bills that look correct still contain at least one of these issues. Up to 49% of medical bills contain errors (CFPB).
- Confusing 85730 (PTT) with 85610 (PT) — both are clotting tests measuring different pathways; each requires separate documentation of clinical indication
- Billing 85730 and 85732 (PTT substitution) together without documentation of why both were performed
- Billing by the ordering physician when the test was entirely performed and interpreted at an outside reference laboratory
If you see 85730 on your bill
Three steps before paying.
1. Get the itemized bill. If your statement only shows a summary, request the CPT-level itemized bill before paying. Generate the request language →
2. Cross-check against the EOB. Compare what your insurer's Explanation of Benefits says you owe versus what the hospital is asking. They disagree more often than people think. Read the bill-vs-EOB guide →
3. Run a free Bill Scan. Upload the bill (and EOB if you have it) and BillBusted will flag the most likely issues with this specific code in your specific state. Run free scan →
Related codes
Other codes in this category.
People who land on 85730 often also see these adjacent codes on the same bill.
CPT
80050 — General health panel; includes CBC w/diff, CMP, TSH
Lab — check for unbundling and duplicate billing.
CPT
80051 — Electrolyte panel; CO2, chloride, potassium, sodium
Lab — check for unbundling and duplicate billing.
CPT
80053 — Comprehensive metabolic panel
If individual blood tests are also on your bill, you may have an unbundling error.
CPT
80055 — Obstetric panel; CBC w/diff, HBsAg, rubella Ab, syphilis, RBC Ab screen, ABO/Rh
Lab — check for unbundling and duplicate billing.
CPT
80061 — Lipid panel (cholesterol)
If you see HDL or LDL listed separately next to 80061, that's unbundling.
Related BillBusted guides
Plain-English reads if you see 85730 on a bill.
85730 FAQ
Plain-English answers.
What does 85730 usually cost?
$5–$15 Medicare allowed (CMS CLFS); $10–$45 commercial; varies by region. Costs vary by region, payer contract, and whether the service was performed in a hospital outpatient department (which adds a facility fee) versus a free-standing clinic.
What's the most common billing error on 85730?
Confusing 85730 (PTT) with 85610 (PT) — both are clotting tests measuring different pathways; each requires separate documentation of clinical indication
What should I do if I see 85730 on my bill?
Request the itemized bill and the matching EOB from your insurer. Compare the units/quantity billed against what you actually received. Run a free BillBusted scan to flag the most likely errors specific to 85730 before paying.
Don't pay 85730 blindly.
The free scan tells you in under 60 seconds whether this charge looks reasonable for your situation.