2020 ICD-10-CM Diagnosis Code Z51.81

Encounter for therapeutic drug level monitoring

    2016 2017 2018 2019 2020 Billable/Specific Code POA Exempt
  • Z51.81 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
  • The 2020 edition of ICD-10-CM Z51.81 became effective on October 1, 2019.
  • This is the American ICD-10-CM version of Z51.81 - other international versions of ICD-10 Z51.81 may differ.
Code Also
Code Also Help
A code also note instructs that 2 codes may be required to fully describe a condition but the sequencing of the two codes is discretionary, depending on the severity of the conditions and the reason for the encounter.
  • any long-term (current) drug therapy (
    ICD-10-CM Diagnosis Code Z79
    • Z79 Long term (current) drug therapy
      • Z79.0 Long term (current) use of anticoagulants and...
        • Z79.01 Long term (current) use of anticoagulants
        • Z79.02 Long term (current) use of antithrombotics/an...
      • Z79.1 Long term (current) use of non-steroidal anti...
      • Z79.2 Long term (current) use of antibiotics
      • Z79.3 Long term (current) use of hormonal contracep...
      • Z79.4 Long term (current) use of insulin
      • Z79.5 Long term (current) use of steroids
        • Z79.51 Long term (current) use of inhaled steroids
        • Z79.52 Long term (current) use of systemic steroids
      • Z79.8 Other long term (current) drug therapy
        • Z79.81 Long term (current) use of agents affecting e...
          • Z79.810 Long term (current) use of selective estrogen...
          • Z79.811 Long term (current) use of aromatase inhibito...
          • Z79.818 Long term (current) use of other agents affec...
        • Z79.82 Long term (current) use of aspirin
        • Z79.83 Long term (current) use of bisphosphonates
        • Z79.84 Long term (current) use of oral hypoglycemic ...
        • Z79.89 Other long term (current) drug therapy
          • Z79.890 Hormone replacement therapy
          • Z79.891 Long term (current) use of opiate analgesic
          • Z79.899 Other long term (current) drug therapy
    Z79.-
    )
Type 1 Excludes
Type 1 Excludes Help
A type 1 excludes note is a pure excludes. It means "not coded here". A type 1 excludes note indicates that the code excluded should never be used at the same time as Z51.81. A type 1 excludes note is for used for when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
  • encounter for blood-drug test for administrative or medicolegal reasons (
    ICD-10-CM Diagnosis Code Z02.83

    Encounter for blood-alcohol and blood-drug test

      2016 2017 2018 2019 2020 Billable/Specific Code POA Exempt
    Use Additional
    • code for findings of alcohol or drugs in blood (R78.-)
    Z02.83
    )
The following code(s) above Z51.81 contain annotation back-references
Annotation Back-References
In this context, annotation back-references refer to codes that contain:
  • Applicable To annotations, or
  • Code Also annotations, or
  • Code First annotations, or
  • Excludes1 annotations, or
  • Excludes2 annotations, or
  • Includes annotations, or
  • Note annotations, or
  • Use Additional annotations
that may be applicable to Z51.81:
  • Z00-Z99
    2020 ICD-10-CM Range Z00-Z99

    Factors influencing health status and contact with health services

    Note
    • Z codes represent reasons for encounters. A corresponding procedure code must accompany a Z code if a procedure is performed. Categories Z00-Z99 are provided for occasions when circumstances other than a disease, injury or external cause classifiable to categories A00-Y89 are recorded as 'diagnoses' or 'problems'. This can arise in two main ways:
    • (a) When a person who may or may not be sick encounters the health services for some specific purpose, such as to receive limited care or service for a current condition, to donate an organ or tissue, to receive prophylactic vaccination (immunization), or to discuss a problem which is in itself not a disease or injury.
    • (b) When some circumstance or problem is present which influences the person's health status but is not in itself a current illness or injury.
    Factors influencing health status and contact with health services
  • Z40-Z53
    2020 ICD-10-CM Range Z40-Z53

    Encounters for other specific health care

    Applicable To
    • Categories Z40-Z53 are intended for use to indicate a reason for care. They may be used for patients who have already been treated for a disease or injury, but who are receiving aftercare or prophylactic care, or care to consolidate the treatment, or to deal with a residual state
    Type 2 Excludes
    • follow-up examination for medical surveillance after treatment (Z08-Z09)
    Encounters for other specific health care
  • Z51
    ICD-10-CM Diagnosis Code Z51

    Encounter for other aftercare and medical care

      2016 2017 - Revised Code 2018 2019 2020 Non-Billable/Non-Specific Code
    Code Also
    • condition requiring care
    Type 1 Excludes
    • follow-up examination after treatment (Z08-Z09)
    Encounter for other aftercare and medical care
  • Z51.8
    ICD-10-CM Diagnosis Code Z51.8

    Encounter for other specified aftercare

      2016 2017 2018 2019 2020 Non-Billable/Non-Specific Code
    Type 1 Excludes
    • holiday relief care (Z75.5)
    Encounter for other specified aftercare
Approximate Synonyms
  • Antihypertensive agent surveillance
  • Medication surveillance, antihypertensive
  • Monitoring growth hormone therapy
  • Monitoring growth hormone therapy done
  • Therapeutic drug monitoring
  • Therapeutic drug monitoring done
Clinical Information
  • (fer-e-sis) a procedure in which blood is collected, part of the blood such as platelets or white blood cells is taken out, and the rest of the blood is returned to the donor.
  • A procedure in which blood is collected, part of the blood such as platelets or white blood cells is taken out, and the rest of the blood is returned to the donor.
  • Any procedure in which blood is withdrawn from a donor, a portion is separated and retained and the remainder is returned to the donor.
Present On Admission
POA Help
"Present On Admission" is defined as present at the time the order for inpatient admission occurs — conditions that develop during an outpatient encounter, including emergency department, observation, or outpatient surgery, are considered POA.
  • Z51.81 is considered exempt from POA reporting.
ICD-10-CM Z51.81 is grouped within Diagnostic Related Group(s) (MS-DRG v37.0):
  • 949 Aftercare with cc/mcc
  • 950 Aftercare without cc/mcc

Convert Z51.81 to ICD-9-CM

Code History
  • 2016 (effective 10/1/2015): New code (first year of non-draft ICD-10-CM)
  • 2017 (effective 10/1/2016): No change
  • 2018 (effective 10/1/2017): No change
  • 2019 (effective 10/1/2018): No change
  • 2020 (effective 10/1/2019): No change
Code annotations containing back-references to Z51.81:
  • Code Also: Z79
    ICD-10-CM Diagnosis Code Z79

    Long term (current) drug therapy

      2016 2017 2018 2019 2020 Non-Billable/Non-Specific Code
    Code Also
    • any therapeutic drug level monitoring (Z51.81)
    Includes
    • long term (current) drug use for prophylactic purposes
    Type 2 Excludes
    • drug abuse and dependence (F11-F19)
    • drug use complicating pregnancy, childbirth, and the puerperium (O99.32-)
    • long term (current) use of oral antidiabetic drugs (Z79.84)
    • long term (current) use of oral hypoglycemic drugs (Z79.84)

Diagnosis Index entries containing back-references to Z51.81:
  • Encounter (with health service) (for) Z76.89
    ICD-10-CM Diagnosis Code Z76.89

    Persons encountering health services in other specified circumstances

      2016 2017 2018 2019 2020 Billable/Specific Code POA Exempt
    Applicable To
    • Persons encountering health services NOS
    • therapeutic drug level monitoring Z51.81
  • Monitoring (encounter for)
    • therapeutic drug level Z51.81

ICD-10-CM Codes Adjacent To Z51.81
Z49.31 Encounter for adequacy testing for hemodialysis
Z49.32 Encounter for adequacy testing for peritoneal dialysis
Z51 Encounter for other aftercare and medical care
Z51.0 Encounter for antineoplastic radiation therapy
Z51.1 Encounter for antineoplastic chemotherapy and immunotherapy
Z51.11 Encounter for antineoplastic chemotherapy
Z51.12 Encounter for antineoplastic immunotherapy
Z51.5 Encounter for palliative care
Z51.6 Encounter for desensitization to allergens
Z51.8 Encounter for other specified aftercare
Z51.81 Encounter for therapeutic drug level monitoring
Z51.89 Encounter for other specified aftercare
Z52 Donors of organs and tissues
Z52.0 Blood donor
Z52.00 Unspecified blood donor
Z52.000 Unspecified donor, whole blood
Z52.001 Unspecified donor, stem cells
Z52.008 Unspecified donor, other blood
Z52.01 Autologous blood donor
Z52.010 Autologous donor, whole blood
Z52.011 Autologous donor, stem cells

Reimbursement claims with a date of service on or after October 1, 2015 require the use of ICD-10-CM codes.