ICDcodes.org
FY2027

O16.1 — Unspecified maternal hypertension, first trimester

BillableUnspecifiedCC

Is O16.1 billable?

Yes, but O16.1 is an unspecified code. O16.1 is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, O16.1 is an unspecified or catch-all code. Payers apply additional scrutiny to unspecified codes and many deny them when the medical record supports a more specific option, so check the documentation before selecting O16.1 — the more specific alternatives are listed below.

O16.1 at a glance

CodeO16.1
DescriptionUnspecified maternal hypertension, first trimester
BillableYes
Code setICD-10-CM FY2027
Valid for encountersOctober 1, 2026 – September 30, 2027

Which MS-DRGs does O16.1 group to?

O16.1 sits in MDC 14 and helps define the logic of 3 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.

  • 817Other Antepartum Diagnoses with O.R. Procedures with MCCsurgical
  • 818Other Antepartum Diagnoses with O.R. Procedures with CCsurgical
  • 819Other Antepartum Diagnoses with O.R. Procedures without CC/MCCsurgical

As a secondary diagnosis, O16.1 is a complication or comorbidity (CC), which can move a stay into a higher-paying DRG.

Excludes1 — never code together — inherited from Chapter 15

The conditions below can never be reported together with O16.1 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.

  • supervision of normal pregnancy (Z34.-)

Use additional code — inherited from Chapter 15

Report an additional code alongside O16.1 to fully describe the condition. O16.1 is sequenced first.

  • code, if applicable, from category Z3A, Weeks of gestation, to identify the specific week of the pregnancy, if known.

Excludes2 — not included here — inherited from Chapter 15

The conditions below are not part of O16.1, but a patient may have both at the same time. When documentation supports it, O16.1 and the excluded code may both be reported.

  • mental and behavioral disorders associated with the puerperium (F53.-)
  • obstetrical tetanus (A34)
  • postpartum necrosis of pituitary gland (E23.0)
  • puerperal osteomalacia (M83.0)

How long has O16.1 existed?

O16.1 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.

Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.

What other codes are in the O16 family? (5)