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Constulose Part D coverage 2027

Constulose is a brand of lactulose. What agents check before quoting it: how many 2027 Part D plans cover it, on which tier, with what restrictions and copays, by plan type, carrier and state.

Coverage at a glance

In 2027, 5,371 of 5,492 Medicare Part D and Medicare Advantage drug plans (97.8%) list Constulose on their formulary, across 282 of 286 formularies. The most common placement is tier 2 (4,748 plans, 88.4% of those covering it). 0 of the covering plans require prior authorization (0%), 0 step therapy and 0 a quantity limit. Generic lactulose is on 5,492 of 5,492 plans (100%).

What a 30-day fill costs

4,819 covering plans charge a flat copay for a 30-day supply at a preferred retail pharmacy after the deductible — median $0, 2,477 of them $0; 552 charge coinsurance instead — median 25% of the drug's cost. Once a member's out-of-pocket drug spending reaches $2,400 in 2027, covered drugs cost $0 for the rest of the year.

What changed since 2026

2026: 5,358 of 5,496 plans covered it (97.5%); 2027: 5,371 of 5,492 (97.8%).

Of 4,367 plans offered in both years, 4 added it to the formulary and 1 dropped it.

Among plans covering it both years, 51 moved it to a higher tier and 261 to a lower one; 0 added prior authorization and 0 removed it.

Tier placement

By plan type

By carrier

By state

Medicare usage

Medicare Part D paid for 254,323 30-day fills of Constulose in 2024 for about 103,675 enrollees, at an average total cost of $18.52 per 30-day fill (CMS Part D Prescribers by Geography and Drug, national).

Related

• Lactulose
• Enulose

Counts are over every Medicare Advantage drug plan and stand-alone Part D plan in the CMS monthly formulary files, excluding employer plans. A plan counts as covering a drug when any strength or form of it is on the plan’s formulary; the tier, prior authorization, step therapy and quantity limit shown are the most favorable version on that formulary. Copays are for a 30-day supply at a preferred retail pharmacy after the deductible. This is a reference for licensed agents, not a plan recommendation; verify with the plan’s formulary before advising a client. Source: CMS Part D formulary files (release 10/08/2026). CMS formulary data.