Ordering Recommendation

Do not use for initial prostate cancer screening; preferred test is Prostate Specific Antigen, Total (0070121) in conjunction with digital rectal exam (DRE). May provide additional prostate cancer risk information for patients with mildly elevated total PSA and a negative DRE.

New York DOH Approval Status

This test is New York state approved.

Specimen Required

Patient Preparation

Serum separator tube. Also acceptable: Green (lithium heparin), Lavender (K2EDTA), or Pink (K2EDTA).

Specimen Preparation

Allow specimen to clot completely at room temperature. Separate serum or plasma from cells ASAP or within 2 hours of collection. Transfer 1 mL serum or plasma to an ARUP Standard Transport Tube. (Min: 0.5 mL)

Storage/Transport Temperature


Unacceptable Conditions

Grossly hemolyzed specimens. Vaginal washings.


After separation from cells: Ambient: 8 hours; Refrigerated: 5 days; Frozen: 3 months


Quantitative Electrochemiluminescent Immunoassay




Within 24 hours

Reference Interval

By report
Results include: PSA-Free, PSA, PSA-Percent Free

Interpretive Data

ARUP uses the Roche Free PSA electrochemiluminescent immunoassay method in conjunction with the Roche PSA electrochemiluminescent immunoassay method to determine the free PSA percentage. Values obtained with different assay methods should not be used interchangeably. The free PSA percentage is an aid in distinguishing prostate cancer from benign prostatic conditions in individuals with a prostate age 50 years and older with a total PSA between 3 and 10ng/mL and negative digital rectal examination findings. Prostatic biopsy is required for the diagnosis of cancer. 

In patients with total PSA concentrations of 4-10 ng/mL, the probability of finding prostate cancer on needle biopsy by age in years is:
% Free PSA
50-59 years
60-69 years
70 years and older
0-10% 49% 58% 65%
11-18% 27% 34% 41%
19-25% 18% 24% 30%
> 25 % 9% 12% 16%
Other factors may help determine the actual risk of prostate cancer in individual patients.

Compliance Category



The free percentage is calculated using the total and free PSA results.

Hotline History


CPT Codes

84153; 84154


Component Test Code* Component Chart Name LOINC
0070121 Prostate Specific Antigen, Total 83112-3
0080207 Prostate Specific Antigen, Free 10886-0
0080209 Prostate Specific Antigen, Percent Free 12841-3
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.


  • Free Prostate Specific Antigen
  • Free PSA
  • PSA Free/Total Ratio
  • PSA ratio
  • PSA Total and Free
  • PSA, Free
  • Total PSA
Prostate Specific Antigen, Free Percentage (Includes Free PSA and Total PSA)