ICD-10 Code O92.4: Hypogalactia diagnosis, coding, and documentation

Key takeaways

ICD-10 Code O92.4 is the billable ICD-10-CM code for hypogalactia, meaning low breast milk production after childbirth.

The code is valid for FY2026, took effect on October 1, 2025, and sits under parent code O92.

Agalactia is coded to O92.3 and means no milk at all, so O92.4 applies only when some milk is produced.

Documentation should confirm postpartum status, name the supply problem, and show pump output or infant weight data.

Practice management software like Pabau attaches the diagnosis code to the encounter, so claims carry the documentation behind them.

ICD-10 Code O92.4 is the billable ICD-10-CM diagnosis code for hypogalactia, or low breast milk production after childbirth. It applies when a postpartum mother produces some milk, but not enough to meet her infant’s needs.

The code took effect on October 1, 2025 and is valid for the FY2026 edition. This guide covers where it sits in the O92 category, the documentation payers check, and how it pairs with lactation support billing.

ICD-10 Code O92.4: Definition, billable status, and FY2026 validity

ICD-10 Code O92.4 describes hypogalactia, the medical term for insufficient breast milk production after childbirth. According to the CDC/NCHS ICD-10-CM web tool, the code is billable and specific. That means it can stand alone on a claim without a more granular sub-code.

The code sits in chapter O00-O9A, which covers pregnancy, childbirth, and the puerperium. Coders in postpartum practices, lactation support programs, and OB/GYN practices meet it whenever a provider documents a maternal breastfeeding difficulty.

What is hypogalactia?

Hypogalactia is partial or reduced breast milk production in a lactating mother after childbirth. It is distinct from agalactia, coded to O92.3, which describes the complete absence of milk secretion. A mother with hypogalactia produces some milk, just not enough to feed her infant fully.

Clinically, it may follow delayed milk letdown, hormonal factors, insufficient breast stimulation, maternal stress, or certain medications. The WHO ICD-10 browser classifies the mechanism as a disorder of lactation rather than a breastfeeding technique problem. That matters, because technique problems point coders toward counseling and education codes instead.

Management usually starts conservatively, with more frequent feeding or pumping, latch correction, and treatment of any underlying cause. For coding, what matters is that the note records the supply level. A test weight, a 24-hour pump volume, or the infant’s weight trajectory each show that production is partial rather than absent.

Synonyms and equivalent terms

Several clinical and lay terms map to ICD-10 Code O92.4 in AAPC’s ICD-10-CM reference. Coders may meet any of these in provider documentation:

• Hypogalactia (primary clinical term)
• Low milk supply
• Insufficient milk production
• Insufficient milk supply
• Decreased milk secretion
• Galactopoiesis disorder (technical/specialist usage)
• Low breast milk supply after childbirth
• Suboptimal lactation

When provider notes use any of these terms for a postpartum patient, O92.4 is the right code, provided the documentation supports it. Structured client records that hold free-text notes beside coded diagnosis fields let coders check the provider’s wording against the code without guesswork.

Where O92.4 sits in the O92 hierarchy

The parent code O92 covers other disorders of breast and lactation associated with childbirth. The category holds retracted nipples, cracked nipples, galactorrhea, suppressed lactation, agalactia, and hypogalactia. CMS ICD-10-CM guidance is clear that coders should select the most specific code the documentation supports.

The full O92 sibling code table, with crosswalks and billable status

The table below shows the complete O92 category, in the order the ICD-10-CM tabular list runs it. It starts at the parent code and covers O92.4 with every sibling. Four of the nine are billable on their own. The rest are header codes that need a fourth or fifth character before a payer will accept them.

The last three columns are the ones you cannot get from a single code lookup. They carry the legacy ICD-9-CM crosswalk from the CMS General Equivalence Mappings. They also give the billable status and the FY2026 effective date for every code.

Two rows of that table change how you work. O92.4 maps to one legacy ICD-9-CM code, 676.84, and O92.79 maps to the same one. Any trend report spanning the 2015 transition therefore cannot separate hypogalactia from other lactation disorders.

Nothing in the category has changed since FY2016 either. Every O92 code carries the same October 1, 2025 effective date for the FY2026 edition. So when an O92 claim is denied, check specificity and documentation before you question the edition year.

ICD-10-CM coding guidelines for O92.4

O92.4 falls in the obstetric chapter, which carries its own sequencing and applicability rules. The ICD-10-CM Official Guidelines for Coding and Reporting, issued by the NCHS, govern how chapter O00-O9A codes are applied. The points below matter most for this code.

• Chapter O codes cover pregnancy, childbirth, and the puerperium. The puerperium generally runs for six weeks after delivery. O92.4 may be assigned for hypogalactia documented inside that window.
• Principal versus secondary diagnosis. When the patient presents primarily for lactation support, O92.4 can be the principal diagnosis. When the supply problem is incidental to another condition, it becomes a secondary code. A postpartum visit that also addresses mood may carry F53.0 alongside it.
• No trimester subcategory. Unlike many obstetric codes, O92.4 carries no trimester-level subdivisions. The single code covers the postpartum period as a whole.
• Watch the global obstetric package. Routine postpartum visits are usually bundled into the delivery package billed under 59510. A lactation problem raised at that visit does not automatically create a separately billable service.
• Age and sex edits apply. O92.4 is a maternity diagnosis for female patients aged 12 to 55. A claim outside that range trips a payer edit, even where the documentation is sound.
• Check the code edition every October. The FY2026 edition took effect on October 1, 2025. Confirm the applicable edition before submitting, because the ICD-10-CM code set is republished each year.

Documentation requirements for O92.4

A billable code is only as strong as the documentation behind it. Digital intake and clinical forms that capture lactation history, feeding frequency, and pump output give coders a clear anchor. A standard medical diagnosis form keeps that wording consistent from one provider to the next.

The following elements should appear in the clinical record when O92.4 is assigned:

• Confirmed postpartum status. The note must establish that the patient is in the puerperium or lactation period after childbirth.
• An explicit diagnosis of hypogalactia or an equivalent term. The provider must document low, insufficient, or reduced milk production. A general note about breastfeeding difficulty never names the supply problem, so it will not support the code.
• Differentiation from agalactia. Where there is any ambiguity, the provider should record that some milk is present but below adequate levels. That single line protects the code from a specificity query.
• A clinical assessment or objective indicator. Feeding frequency, infant weight gain, or pump output data support the diagnosis. They also demonstrate medical necessity for any lactation support service billed with it.
• A plan of care. Documented lactation counseling, a supplementation plan, or a referral strengthens the medical necessity case for the encounter.

Practices using integrated claims management software can attach diagnosis codes to the encounter at the point of care. That shortens the distance between the clinical note and the claim.

Postpartum care is rarely a single-provider job. A shared SBAR report keeps the supply problem visible at handoff, as the patient moves between the lactation consultant, the midwife, and the OB/GYN.

When to use O92.4 instead of a sibling code

The O92 category holds several codes that describe different lactation and breast disorders. Choosing between them is the most common source of coding error in postpartum encounters. The comparison below covers the codes most often confused with O92.4.

How hypogalactia differs from agalactia

A common error is assigning O92.3 because a mother has not yet established breastfeeding, when the provider has documented partial supply. Always go back to the exact language in the clinical note. Where the note is ambiguous, query the provider rather than defaulting to O92.70.

One word in the note can move the code. O92.3 carries an Excludes1 note that sends elective, secondary, and therapeutic agalactia to O92.5. A mother whose lactation was deliberately stopped is coded O92.5, however the provider words the absence of milk.

Practices running complex reproductive health billing meet the O92 category alongside fertility claims coded with IVF CPT codes. Applying the lactation code at an encounter date inside the puerperium window keeps the claim clear of a chapter mismatch.

Billing and reimbursement for postpartum lactation support

O92.4 is the ICD-10-CM diagnosis code, so reimbursement depends on the procedure code paired with it. Lactation support visits are usually billed under evaluation and management codes, or under lactation-specific counseling codes. Group education classes carry their own HCPCS code, S9443.

Coverage for lactation support varies by payer and plan. The Affordable Care Act requires most non-grandfathered plans to cover breastfeeding support without cost sharing. O92.4 can therefore help justify medical necessity for a reimbursable lactation service. Verify the CPT pairing against current CMS guidance and the payer’s own policy before submission.

• Lactation consultant services. Reimbursement for International Board Certified Lactation Consultants varies by state and payer. The supervising physician or midwife often bills on their behalf, so check which NPI type belongs on the claim.
• Postpartum OB/GYN visits. When hypogalactia is addressed during a standard postpartum visit, O92.4 is added as a secondary diagnosis alongside the primary reason for the encounter.
• Hospital inpatient lactation support. Inpatient sequencing rules apply, so the principal diagnosis reflects the condition chiefly responsible for the admission. O92.4 is almost always secondary there.
• Documentation of medical necessity. Payer audits in postpartum care look for documented clinical need. Showing that the low supply affects infant nutrition or maternal health strengthens the claim.

Practices that also bill counseling and education services should check how lactation counseling is classified. It may sit under health behavior intervention codes rather than standard E&M coding, and that choice changes the supporting diagnoses on the claim.

How Pabau keeps postpartum coding and claims aligned

In many postpartum practices the lactation note lives in one system and the claim is built in another. The coder reads the note days later, finds no wording that separates partial supply from absent supply, and sends a query. The visit sits unbilled until the answer comes back.

Practice management software like Pabau keeps the note and the claim in one record. Providers record lactation history, feeding frequency, and pump output on custom forms. The diagnosis code is attached to the encounter as it is charted, so nothing is re-keyed later.

Pelvic health practices and OB/GYN teams both work from that same chart. The result is fewer coder queries, fewer specificity denials, and a shorter path from the postpartum visit to a paid claim. Denial patterns by code show up in reporting, so a recurring O92 problem surfaces early.

Streamline postpartum care billing with Pabau

Pabau helps OB/GYN and postpartum teams attach accurate ICD-10 diagnosis codes at the point of care. Fewer coding queries mean faster reimbursement.

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Conclusion

One judgment decides this code. If the mother produces some milk, O92.4 is correct. If she produces none, the code is O92.3, and everything else in this article exists to keep that distinction visible in the chart.

Fix the documentation habit and the coding follows. Ask providers to record the supply level and one objective measure at every postpartum lactation visit. That single line settles the question before a coder has to ask it.

Pabau holds that record and the claim in the same place, so postpartum visits go out coded the way they were documented. Book a demo to see how it handles obstetric and postpartum billing.

Continue your research

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Billing a group lactation education class? S9443 explains how the class is reported and where payer coverage tends to stop.

Coding an injury sustained during the delivery itself? O71.9 walks through obstetric trauma coding and the notes that support it.

Billing the delivery episode rather than a single visit? 59400 sets out what the global obstetric package includes and what stays separate.

Sending nutrition guidance home with a new mother? Postpartum diet plan is a ready-made handout you can adapt to your own recovery advice.

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