New real-world data suggest that older adults who stay on tirzepatide (Zepbound; Eli Lilly and Company) for weight management accumulate health care cost savings that grow over time and, by 12 to 18 months, may exceed what Medicare pays for the drug under its GLP-1 Bridge program
For pharmacists counseling patients on cost and persistence, the findings add an economic argument to the clinical case for keeping eligible patients on therapy and land squarely in the middle of an active coverage debate.1,2
What the Study Found
The matched cohort analysis, published in Diabetes, Obesity and Metabolism, compared 15,843 adults aged older than 55 with overweight or obesity and without type 2 diabetes who initiated tirzepatide against an equal number of propensity-matched, untreated controls
Using a difference-in-differences framework and excluding the cost of tirzepatide itself, the primary inverse-probability-of-censoring-weighting (IPCW) analysis found all-cause health care costs were $145 per person per month lower during the 6-to-12-month window (a 12.3% reduction; P = .022)) and $319 lower during the 12-to-18-month window (a 25.4% reduction; P = .023) relative to controls. A supporting pairwise censoring analysis showed larger offsets of $181 (P = .021) and $607 (P = .023) per person per month over the same periods.1
Notably, the divergence was driven less by falling costs in the tirzepatide group than by rising costs in the untreated group, whose all-cause monthly costs climbed from $1031 at baseline to $1244 by 12 to 18 months while the tirzepatide group stayed largely flat
Fewer Hospital and Emergency Department Visits
A key driver of the cost separation was acute care utilization. In the primary analysis, adults treated with tirzepatide had lower rates of combined inpatient admissions and emergency department (ED) visits across every follow-up period, with incidence rate ratios of 0.86 (95% CI, 0.74 to 0.99; P = .033) at 3 to 6 months, 0.76 (95% CI, 0.64 to 0.89; P = .001) at 6 to 12 months, and 0.69 (95% CI, 0.50 to 0.94; P = .021) at 12 to 18 months. Rates of routine outpatient and office visits were numerically higher in the tirzepatide group, which the authors interpreted as greater engagement with routine care rather than a cost concern.1,2
A Lilly spokesperson noted that the burden extends well beyond weight itself, framing the utilization findings in the context of obesity as a chronic disease: “In the US, 2 in 5 adults 65 and older live with obesity,” the spokesperson said, describing it as a condition “associated with increased risk of cardiovascular disease, type 2 diabetes, and osteoarthritis, conditions that contribute significantly to overall health care costs.”2
Why the Numbers Matter for Medicare
The findings arrive as the Centers for Medicare & Medicaid Services runs the Medicare GLP-1 Bridge, a demonstration launched July 1, 2026, that gives eligible Part D beneficiaries access to semaglutide (Wegovy; Novo Nordisk), tirzepatide, and orforglipron (Foundayo; Eli Lilly and Company) for weight management at a flat $50 monthly co-pay through December 31, 2027
Under the program, tirzepatide carries a net cost to Medicare of $195 per month. The authors framed their central estimate—a $319 monthly offset by 12 to 18 months—as evidence that downstream savings may cover, and eventually exceed, that net drug cost among patients who stay on treatment.1,3
That interpretation carries important caveats for pharmacists to keep in view. Because the analysis excluded tirzepatide’s own cost, the reported figures reflect savings that could offset the price rather than the net budget impact of treatment overall
A Lilly spokesperson explained that the exclusion was deliberate: “Given the changing pricing dynamic of Zepbound and the absence of confidential rebate data in the dataset, the study did not include Zepbound treatment costs in the healthcare cost analysis,” adding that the results “should be interpreted as the estimated health care cost offsets that could be weighed against the price of Zepbound, depending on a given stakeholder’s net cost.”2
The findings also apply only to adults who remained persistent on therapy; anyone who discontinued was censored, so the results cannot be extrapolated to patients who stop. Fewer than 10% of participants remained uncensored through the 12-to-18-month window, which limits the precision of the longest-term estimates.1
The Persistence and Access Problem
The economic case hinges on patients staying on therapy, which, in practice, runs into coverage barriers pharmacists know well. At recent Pharmacy Times Clinical Forums, panelists described insurance coverage as the single largest obstacle in obesity care, citing step therapy requirements, mandated titration even for stable patients, and prior authorization hurdles under the Bridge itself. Early implementation reporting has also flagged claim-routing errors in which Bridge claims submitted through a patient’s standard Part D plan are automatically rejected, requiring pharmacists to confirm claims are routed to the program’s dedicated processor.3,4
