2020 ICD-10-CM Diagnosis Code O26.40

Herpes gestationis, unspecified trimester

    2016 2017 2018 2019 2020 Billable/Specific Code Maternity Dx (12-55 years)
  • O26.40 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 O26.40 became effective on October 1, 2019.
  • This is the American ICD-10-CM version of O26.40 - other international versions of ICD-10 O26.40 may differ.
ICD-10-CM Coding Rules
  • O26.40 is applicable to maternity patients aged 12 - 55 years inclusive.
The following code(s) above O26.40 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 O26.40:
  • O00-O9A
    2020 ICD-10-CM Range O00-O9A

    Pregnancy, childbirth and the puerperium

    • Codes from this chapter are for use for conditions related to or aggravated by the pregnancy, childbirth, or by the puerperium (maternal causes or obstetric causes)
    • Trimesters are counted from the first day of the last menstrual period. They are defined as follows:
    • 1st trimester- less than 14 weeks 0 days
    • 2nd trimester- 14 weeks 0 days to less than 28 weeks 0 days
    • 3rd trimester- 28 weeks 0 days until delivery
    Type 1 Excludes
    • supervision of normal pregnancy (Z34.-)
    Type 2 Excludes
    • mental and behavioral disorders associated with the puerperium (F53.-)
    • obstetrical tetanus (A34)
    • postpartum necrosis of pituitary gland (E23.0)
    • puerperal osteomalacia (M83.0)
    Use Additional
    • code from category Z3A, Weeks of gestation, to identify the specific week of the pregnancy, if known.
    Pregnancy, childbirth and the puerperium
  • O20-O29
    2020 ICD-10-CM Range O20-O29

    Other maternal disorders predominantly related to pregnancy

    Type 2 Excludes
    • maternal care related to the fetus and amniotic cavity and possible delivery problems (O30-O48)
    • maternal diseases classifiable elsewhere but complicating pregnancy, labor and delivery, and the puerperium (O98-O99)
    Other maternal disorders predominantly related to pregnancy
Approximate Synonyms
  • Herpes gestationis
  • Herpes gestationis in pregnancy
Clinical Information
  • A rare autoimmune bullous dermatitis that develops during pregnancy, most often during the second and third trimesters.
  • An itching, autoimmune, bullous skin disease that occurs during the last two trimesters of pregnancy and puerperium. It also affects non-pregnant females with tissue of placenta origin, such as choriocarcinoma; or hydatidiform mole. It exhibits antigenic and clinical similarity to bullous pemphigoid (pemphigoid, bullous). This disease does not involve herpes viruses (old name, herpes gestationis).
ICD-10-CM O26.40 is grouped within Diagnostic Related Group(s) (MS-DRG v37.0):
  • 817 Other antepartum diagnoses with o.r. Procedure with mcc
  • 818 Other antepartum diagnoses with o.r. Procedure with cc
  • 819 Other antepartum diagnoses with o.r. Procedure without cc/mcc
  • 831 Other antepartum diagnoses without o.r. Procedure with mcc
  • 832 Other antepartum diagnoses without o.r. Procedure with cc
  • 833 Other antepartum diagnoses without o.r. Procedure without cc/mcc

Convert O26.40 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
ICD-10-CM Codes Adjacent To O26.40
O26.20 …… unspecified trimester
O26.21 …… first trimester
O26.22 …… second trimester
O26.23 …… third trimester
O26.3 Retained intrauterine contraceptive device in pregnancy
O26.30 …… unspecified trimester
O26.31 …… first trimester
O26.32 …… second trimester
O26.33 …… third trimester
O26.4 Herpes gestationis
O26.40 …… unspecified trimester
O26.41 …… first trimester
O26.42 …… second trimester
O26.43 …… third trimester
O26.5 Maternal hypotension syndrome
O26.50 …… unspecified trimester
O26.51 …… first trimester
O26.52 …… second trimester
O26.53 …… third trimester
O26.6 Liver and biliary tract disorders in pregnancy, childbirth and the puerperium
O26.61 Liver and biliary tract disorders in pregnancy

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